The zero-day exploits of Operation WizardOpium – 10 minute mail

Back in October 2019 we detected a classic watering-hole attack on a North Korea-related news site that exploited a chain of Google Chrome and Microsoft Windows zero-days. While we’ve already published blog posts briefly describing this operation (available here and here), in this blog post we’d like to take a deep technical dive into the exploits and vulnerabilities used in this attack.

Google Chrome remote code execution exploit

In the original blog post we described the exploit loader responsible for initial validation of the target and execution of the next stage JavaScript code containing the full browser exploit. The exploit is huge because, besides code, it contains byte arrays with shellcode, a Portable Executable (PE) file and WebAssembly (WASM) module used in the later stages of exploitation. The exploit abused a vulnerability in the WebAudio OfflineAudioContext interface and was targeting two release builds of Google Chrome 76.0.3809.87 and 77.0.3865.75. However, the vulnerability was introduced long before that and much earlier releases with a WebAudio component are also vulnerable. At the time of our discovery the current version of Google Chrome was 78, and while this version was also affected, the exploit did not support it and had a number of checks to ensure that it would only be executed on affected versions to prevent crashes. After our report, the vulnerability was assigned CVE-2019-13720 and was fixed in version 78.0.3904.87 with the following commit. A use-after-free (UAF) vulnerability, it could be triggered due to a race condition between the Render and Audio threads:

As you can see, when the audio buffer is set to null in ConvolverNode and an active buffer already exists within the Reverb object, the function SetBuffer() can destroy reverb_ and shared_buffer_ objects.

These objects might still be in use by the Render thread because there is no proper synchronization between the two threads in the code. A patch added two missing locks (graph lock and process lock) for when the buffer is nullified.

The exploit code was obfuscated, but we were able to fully reverse engineer it and reveal all the small details. By looking at the code, we can see the author of the exploit has excellent knowledge of the internals of specific Google Chrome components, especially the PartitionAlloc memory allocator. This can clearly be seen from the snippets of reverse engineered code below. These functions are used in the exploit to retrieve useful information from internal structures of the allocator, including: SuperPage address, PartitionPage address by index inside the SuperPage, the index of the used PartitionPage and the address of PartitionPage metadata. All constants are taken from partition_alloc_constants.h:

It’s interesting that the exploit also uses the relatively new built-in BigInt class to handle 64-bit values; authors usually use their own primitives in exploits.

At first, the code initiates OfflineAudioContext and creates a huge number of IIRFilterNode objects that are initialized via two float arrays.

After that, the exploit begins the initial stage of exploitation and tries to trigger a UAF bug. For that to work the exploit creates the objects that are needed for the Reverb component. It creates another huge OfflineAudioContext object and two ConvolverNode objects – ScriptProcessorNode to start audio processing and AudioBuffer for the audio channel.

This function is executed recursively. It fills the audio channel buffer with zeros, starts rendering offline and at the same time runs a loop that nullifies and resets the channel buffer of the ConvolverNode object and tries to trigger a bug. The exploit uses the later() function to simulate the Sleep function, suspend the current thread and let the Render and Audio threads finish execution right on time:

During execution the exploit checks if the audio channel buffer contains any data that differs from the previously set zeroes. The existence of such data would mean the UAF was triggered successfully and at this stage the audio channel buffer should contain a leaked pointer.

The PartitionAlloc memory allocator has a special exploit mitigation that works as follows: when the memory region is freed, it byteswaps the address of the pointer and after that the byteswapped address is added to the FreeList structure. This complicates exploitation because the attempt to dereference such a pointer will crash the process. To bypass this technique the exploit uses the following primitive that simply swaps the pointer back:

The exploit uses the leaked pointer to get the address of the SuperPage structure and verifies it. If everything goes to plan, then it should be a raw pointer to a temporary_buffer_ object of the ReverbConvolverStage class that is passed to the callback function initialUAFCallback.

The exploit uses the leaked pointer to get the address of the raw pointer to the feedforward_ array with the AudioArray type that is present in the IIRProcessor object created with IIRFilterNode. This array should be located in the same SuperPage, but in different versions of Chrome this object is created in different PartitionPages and there is a special code inside initialUAFCallback to handle that.

The vulnerability is actually triggered not once but twice. After the address of the right object is acquired, the vulnerability is exploited again. This time the exploit uses two AudioBuffer objects of different sizes, and the previously retrieved address is sprayed inside the larger AudioBuffer. This function also executes recursively.

This time the exploit uses the function getFrequencyResponse() to check if exploitation was successful. The function creates an array of frequencies that is filled with a Nyquist filter and the source array for the operation is filled with zeroes.

If the resulting array contains a value other than π, it means exploitation was successful. If that’s the case, the exploit stops its recursion and executes the function finalUAFCallback to allocate the audio channel buffer again and reclaim the previously freed memory. This function also repairs the heap to prevent possible crashes by allocating various objects of different sizes and performing defragmentation of the heap. The exploit also creates BigUint64Array, which is used later to create an arbitrary read/write primitive.

Heap defragmentation is performed with multiple calls to the improvised collectGarbage function that creates a huge ArrayBuffer in a loop.

After those steps, the exploit executes the function kickPayload() passing the previously created BigUint64Array containing the raw pointer address of the previously freed AudioArray’s data.

The exploit manipulates the PartitionPage metadata of the freed object to achieve the following behavior. If the address of another object is written in BigUint64Array at index zero and if a new 8-byte object is created and the value located at index 0 is read back, then a value located at the previously set address will be read. If something is written at index 0 at this stage, then this value will be written to the previously set address instead.

After the building of the arbitrary read/write primitives comes the final stage – executing the code. The exploit achieves this by using a popular technique that exploits the Web Assembly (WASM) functionality. Google Chrome currently allocates pages for just-in-time (JIT) compiled code with read/write/execute (RWX) privileges and this can be used to overwrite them with shellcode. At first, the exploit initiates a “dummy” WASM module and it results in the allocation of memory pages for JIT compiled code.

To execute the exported function wasmFuncA, the exploit creates a FileReader object. When this object is initiated with data it creates a FileReaderLoader object internally. If you can parse PartitionAlloc allocator structures and know the size of the next object that will be allocated, you can predict which address it will be allocated to. The exploit uses the getPartitionPageFreeListHeadEntryBySlotSize() function with the provided size and gets the address of the next free block that will be allocated by FileReaderLoader.

The exploit obtains this address twice to find out if the FileReaderLoader object was created and if the exploit can continue execution. The exploit sets the exported WASM function to be a callback for a FileReader event (in this case, an onerror callback) and because the FileReader type is derived from EventTargetWithInlineData, it can be used to get the addresses of all its events and the address of the JIT compiled exported WASM function.

The variable stubAddr contains the address of the page with the stub code that jumps to the JIT compiled WASM function. At this stage it’s sufficient to overwrite it with shellcode. To do so, the exploit uses the function getPartitionPageFreeListHeadEntryBySlotSize() again to find the next free block of 0x20 bytes, which is the size of the structure for the ArrayBuffer object. This object is created when the exploit creates a new audio buffer.

The exploit uses arbitrary read/write primitives to get the address of the DataHolder class that contains the raw pointer to the data and size of the audio buffer. The exploit overwrites this pointer with stubAddr and sets a huge size.

Now all that’s needed is to implant a Uint8Array object into the memory of this audio buffer and place shellcode there along with the Portable Executable that will be executed by the shellcode.

To prevent the possibility of a crash the exploit clears the pointer to the top of the FreeList structure used by the PartitionPage.

Now, in order to execute the shellcode, it’s enough to call the exported WASM function.

Microsoft Windows elevation of privilege exploit

The shellcode appeared to be a Reflective PE loader for the Portable Executable module that was also present in the exploit. This module mostly consisted of the code to escape Google Chrome’s sandbox by exploiting the Windows kernel component win32k for the elevation of privileges and it was also responsible for downloading and executing the actual malware. On closer analysis, we found that the exploited vulnerability was in fact a zero-day. We notified Microsoft Security Response Center and they assigned it CVE-2019-1458 and fixed the vulnerability. The win32k component has something of bad reputation. It has been present since Windows NT 4.0 and, according to Microsoft, it is responsible for more than 50% of all kernel security bugs. In the last two years alone Kaspersky has found five zero-days in the wild that exploited win32k vulnerabilities. That’s quite an interesting statistic considering that since the release of Windows 10, Microsoft has implemented a number of mitigations aimed at complicating exploitation of win32k vulnerabilities and the majority of zero-days that we found exploited versions of Microsoft Windows prior to the release of Windows 10 RS4. The elevation of privilege exploit used in Operation WizardOpium was built to support Windows 7, Windows 10 build 10240 and Windows 10 build 14393. It’s also important to note that Google Chrome has a special security feature called Win32k lockdown developed and supported by James Forshaw of Google Project Zero. This security feature eliminates the whole win32k attack surface by disabling access to win32k syscalls from inside Chrome processes. Unfortunately, Win32k lockdown is only supported on machines running Windows 10. So, it’s fair to assume that Operation WizardOpium targeted users running Windows 7.

CVE-2019-1458 is an Arbitrary Pointer Dereference vulnerability. In win32k Window objects are represented by a tagWND structure. There are also a number of classes based on this structure: ScrollBar, Menu, Listbox, Switch and many others. The FNID field of tagWND structure is used to distinguish the type of class. Different classes also have various extra data appended to the tagWND structure. This extra data is basically just different structures that often include kernel pointers. Besides that, in the win32k component there’s a syscall SetWindowLongPtr that can be used to set this extra data (after validation of course). It’s worth noting that SetWindowLongPtr was related to a number of vulnerabilities in the past (e.g., CVE-2010-2744, CVE-2016-7255, and CVE-2019-0859). There’s a common issue when pre-initialized extra data can lead to system procedures incorrectly handling. In the case of CVE-2019-1458, the validation performed by SetWindowLongPtr was just insufficient.

A check for the index parameter would have prevented this bug, but prior to the patch the values for FNID_DESKTOP, FNID_SWITCH, FNID_TOOLTIPS inside the mpFnid_serverCBWndProc table were not initialized, rendering this check useless and allowing the kernel pointers inside the extra data to be overwritten.

Triggering the bug is quite simple: at first, you create a Window, then NtUserMessageCall can be used to call any system class window procedure.

It’s important to provide the right message and dwType parameters. The message needs to be equal to WM_CREATE. dwType is converted to fnIndex internally with the following calculation: (dwType + 6) & 0x1F. The exploit uses a dwType equal to 0xE0. It results in an fnIndex equal to 6 which is the function index of xxxSwitchWndProc and the WM_CREATE message sets the FNID field to be equal to FNID_SWITCH.

The vulnerability in NtUserSetWindowLongPtr can then be used to overwrite the extra data at index zero, which happens to be a pointer to a structure containing information about the Switch Window. In other words, the vulnerability makes it possible to set some arbitrary kernel pointer that will be treated as this structure.

At this stage it’s enough to call NtUserMessageCall again, but this time with a message equal to WM_ERASEBKGND. This results in the execution of the function xxxPaintSwitchWindow that increments and decrements a couple of integers located by the pointer that we previously set.

An important condition for triggering the exploitable code path is that the ALT key needs to be pressed.

Exploitation is performed by abusing Bitmaps. For successful exploitation a few Bitmaps need to be allocated next to each other, and their kernel addresses need to be known. To achieve this, the exploit uses two common kernel ASLR bypass techniques. For Windows 7 and Windows 10 build 10240 (Threshold 1) the Bitmap kernel addresses are leaked via the GdiSharedHandleTable technique: in older versions of the OS there is a special table available in the user level that holds the kernel addresses of all GDI objects present in the process. This particular technique was patched in Windows 10 build 14393 (Redstone 1), so for this version the exploit uses another common technique that abuses Accelerator Tables (patched in Redstone 2). It involves creating a Create Accelerator Table object, leaking its kernel address from the gSharedInfo HandleTable available in the user level, and then freeing the Accelerator Table object and allocating a Bitmap reusing the same memory address.

The whole exploitation process works as follows: the exploit creates three bitmaps located next to each other and their addresses are leaked. The exploit prepares Switch Window and uses a vulnerability in NtUserSetWindowLongPtr to set an address pointing near the end of the first Bitmap as Switch Window extra data. Bitmaps are represented by a SURFOBJ structure and the previously set address needs to be calculated in a way that will make the xxxPaintSwitchWindow function increment the sizlBitmap field of the SURFOBJ structure for the Bitmap allocated next to the first one. The sizlBitmap field indicates the bounds of the pixel data buffer and the incremented value will allow the use of the function SetBitmapBits() to perform an out-of-bounds write and overwrite the SURFOBJ of the third Bitmap object.

The pvScan0 field of the SURFOBJ structure is an address of the pixel data buffer, so the ability to overwrite it with an arbitrary pointer results in arbitrary read/write primitives via the functions GetBitmapBits()/SetBitmapBits(). The exploit uses these primitives to parse the EPROCESS structure and steal the system token. To get the kernel address of the EPROCESS structure, the exploit uses the function EnumDeviceDrivers. This function works according to its MSDN description and it provides a list of kernel addresses for currently loaded drivers. The first address in the list is the address of ntkrnl and to get the offset to the EPROCESS structure the exploit parses an executable in search for the exported PsInitialSystemProcess variable.

It’s worth noting that this technique still works in the latest versions of Windows (tested with Windows 10 19H1 build 18362). Stealing the system token is the most common post exploitation technique that we see in the majority of elevation of privilege exploits. After acquiring system privileges the exploit downloads and executes the actual malware.


It was particularly interesting for us to examine the Chrome exploit because it was the first Google Chrome in-the-wild zero-day encountered for a while. It was also interesting that it was used in combination with an elevation of privilege exploit that didn’t allow exploitation on the latest versions of Windows mostly due to the Win32k lockdown security feature of Google Chrome. With regards to privilege elevation, it was also interesting that we found another 1-day exploit for this vulnerability just one week after the patch, indicating how simple it is to exploit this vulnerability.

We would like to thank the Google Chrome and Microsoft security teams for fixing these vulnerabilities so quickly. Google was generous enough to offer a bounty for CVE-2019-13720. The reward was donated to charity and Google matched the donation.

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IT threat evolution Q1 2020. Statistics – 10 minute mail

These statistics are based on detection verdicts for Kaspersky products received from users who consented to providing statistical data.

Quarterly figures

According to Kaspersky Security Network,

  • Kaspersky solutions blocked 726,536,269 attacks launched from online resources in 203 countries across the globe.
  • A total of 442,039,230 unique URLs were recognized as malicious by Web Anti-Virus components.
  • Attempted infections by malware designed to steal money via online access to bank accounts were logged on the computers of 249,748 unique users.
  • Ransomware attacks were defeated on the computers of 178,922 unique users.
  • Our File Anti-Virus detected 164,653,290 unique malicious and potentially unwanted objects.
  • Kaspersky products for mobile devices detected:
    • 1,152,662 malicious installation packages
    • 42,115 installation packages for mobile banking trojans
    • 4339 installation packages for mobile ransomware trojans

Mobile threats

Quarter events

Q1 2020 will be remembered primarily for the coronavirus pandemic and cybercriminals’ exploitation of the topic. In particular, the creators of a new modification of the Ginp banking trojan renamed their malware Coronavirus Finder and then began offering it for €0.75 disguised as an app supposedly capable of detecting nearby people infected with COVID-19. Thus, the cybercriminals tried not only to scam users by exploiting hot topics, but to gain access to their bank card details. And, because the trojan remains on the device after stealing this data, the cybercriminals could intercept text messages containing two-factor authorization codes and use the stolen data without the victim’s knowledge.

Another interesting find this quarter was Cookiethief, a trojan designed to steal cookies from mobile browsers and the Facebook app. In the event of a successful attack, the malware provided its handler with access to the victim’s account, including the ability to perform various actions in their name, such as liking, reposting, etc. To prevent the service from spotting any abnormal activity in the hijacked profile, the trojan contains a proxy module through which the attackers issue commands.

The third piece of malware that caught our attention this reporting quarter was trojan-Dropper.AndroidOS.Shopper.a. It is designed to help cybercriminals to leave fake reviews and drive up ratings on Google Play. The attackers’ goals here are obvious: to increase the changes of their apps getting published and recommended, and to lull the vigilance of potential victims. Note that to rate apps and write reviews, the trojan uses Accessibility Services to gain full control over the other app: in this case, the official Google Play client.

Mobile threat statistics

In Q1 2020, Kaspersky’s mobile products and technologies detected 1,152,662 malicious installation packages, or 171,669 more than in the previous quarter.

Number of malicious installation packages detected, Q1 2019 – Q1 2020 (download)

Starting in Q2 2019, we have seen a steady rise in the number of mobile threats detected. Although it is too early to sound the alarm (2019 saw the lowest number of new threats in recent years), the trend is concerning.

Distribution of detected mobile apps by type

Distribution of newly detected mobile programs by type, Q1 2020 and Q4 2019 (download)

Of all the threats detected in Q1, half were unwanted adware apps (49.9%), their share having increased by 19 p.p. compared to the previous quarter. Most often, we detected members of the HiddenAd and Ewind families, with a combined slice of 40% of all detected adware threats, as well as the FakeAdBlocker family (12%).

Potentially unwanted RiskTool apps (28.24%) took second place; the share of this type of threat remained almost unchanged. The Smsreg (49% of all detected threats of this class), Agent (17%) and Dnotua (11%) families were the biggest contributors. Note that in Q1, the number of detected members of the Smsreg family increased by more than 50 percent.

In third place were Trojan-Dropper-type threats (9.72%). Although their share decreased by 7.63 p.p. against the previous quarter, droppers remain one of the most common classes of mobile threats. Ingopack emerged as Q1’s leading family with a massive 71% of all Trojan-Dropper threats, followed by Waponor (12%) and Hqwar (8%) far behind.

It is worth noting that mobile droppers are most often used for installing financial malware, although some financial threats can spread without their help. The share of these self-sufficient threats is quite substantial: in particular, the share of Trojan-Banker in Q1 increased by 2.1 p.p. to 3.65%.

Top 20 mobile malware programs

Note that this malware rankings do not include potentially dangerous or unwanted programs such as RiskTool or adware.

Verdict %*
1 DangerousObject.Multi.Generic 44.89
2 Trojan.AndroidOS.Boogr.gsh 9.09
3 DangerousObject.AndroidOS.GenericML 7.08
4 Trojan-Downloader.AndroidOS.Necro.d 4.52
5 2.73
6 Trojan-Downloader.AndroidOS.Helper.a 2.45
7 Trojan.AndroidOS.Handda.san 2.31
8 Trojan-Dropper.AndroidOS.Necro.z 2.30
9 Trojan.AndroidOS.Necro.a 2.19
10 Trojan-Downloader.AndroidOS.Necro.b 1.94
11 Trojan-Dropper.AndroidOS.Hqwar.gen 1.82
12 Trojan-Dropper.AndroidOS.Helper.l 1.50
13 1.46
14 Trojan-Dropper.AndroidOS.Lezok.p 1.46
15 Trojan-Banker.AndroidOS.Rotexy.e 1.43
16 Trojan-Dropper.AndroidOS.Penguin.e 1.42
17 Trojan-SMS.AndroidOS.Prizmes.a 1.39
18 Trojan.AndroidOS.Dvmap.a 1.24
19 Trojan.AndroidOS.Agent.rt 1.21
20 Trojan.AndroidOS.Vdloader.a 1.18

* Unique users attacked by this malware as a percentage of all users of Kaspersky mobile products that were attacked.

First place in our Top 20 as ever went to DangerousObject.Multi.Generic (44.89%), the verdict we use for malware detected using cloud technology. They are triggered when the antivirus databases still lack the data for detecting a malicious program, but the Kaspersky Security Network cloud already contains information about the object. This is basically how the latest malware is detected.

Second and third places were claimed by Trojan.AndroidOS.Boogr.gsh (9.09%) and DangerousObject.AndroidOS.GenericML (7,08%) respectively. These verdicts are assigned to files that are recognized as malicious by our machine-learning systems.

In fourth (Trojan-Downloader.AndroidOS.Necro.d, 4.52%) and tenth (Trojan-Downloader.AndroidOS.Necro.b, 1.94%) places are members of the Necro family, whose main task is to download and install modules from cybercriminal servers. Eighth-placed Trojan-Dropper.AndroidOS.Necro.z (2.30%) acts in a similar way, extracting from itself only those modules that it needs. As for Trojan.AndroidOS.Necro.a, which took ninth place (2.19%), cybercriminals assigned it a different task: the trojan follows advertising links and clicks banner ads in the victim’s name. (2.73%) claimed fifth spot. As soon as it runs, the malware hides its icon on the list of apps and continues to operate in the background. The trojan’s payload can be other trojan programs or adware apps.

Sixth place went to Trojan-Downloader.AndroidOS.Helper.a (2.45%), which is what Trojan-Downloader.AndroidOS.Necro usually delivers. Helper.a is tasked with downloading arbitrary code from the cybercriminals’ server and running it.

The verdict Trojan.AndroidOS.Handda.san (2.31%) in seventh place is a group of diverse trojans that hide their icons, gain Device Admin rights on the device, and use packers to evade detection.

Trojan-Banker.AndroidOS.Rotexy.e (1.43%) and Trojan-Dropper.AndroidOS.Penguin.e (1.42%) warrant a special mention. The former is the only banking trojan in the top 20 this past quarter. The Rotexy family is all of six years old, and its members have the functionality to steal bank card details and intercept two-factor payment authorization messages. In turn, the first member of the Penguin dropper family was only detected last July and had gained significant popularity by Q1 2020.

Geography of mobile threats


Map of infection attempts by mobile malware, Q1 2020 (download)

Top 10 countries by share of users attacked by mobile threats

Country* %**
1 Iran 39.56
2 Algeria 21.44
3 Bangladesh 18.58
4 Nigeria 15.58
5 Lebanon 15.28
6 Tunisia 14.94
7 Pakistan 13.99
8 Kuwait 13.91
9 Indonesia 13.81
10 Cuba 13.62

* Excluded from the rankings are countries with relatively few users of Kaspersky mobile products (under 10,000).
** Unique users attacked as a percentage of all users of Kaspersky mobile products in the country.

In Q1 2020, the leader by share of attacked users was Iran (39.56%). Inhabitants of this country most frequently encountered adware apps from the Notifyer family, as well as Telegram clone apps. In second place was Algeria (21.44%), where adware apps were also distributed, but this time it was the HiddenAd and FakeAdBlocker families. Third place was taken by Bangladesh (18.58%), where half of the top 10 mobile threats consisted of adware in the HiddenAd family.

Mobile banking trojans

During the reporting period, we detected 42,115 installation packages of mobile banking trojans. This is the highest value in the past 18 months, and more than 2.5 times higher than in Q4 2019. The largest contributions to the statistics came from the Trojan-Banker.AndroidOS.Agent (42.79% of all installation packages detected), Trojan-Banker.AndroidOS.Wroba (16.61%), and Trojan-Banker.AndroidOS.Svpeng (13.66%) families.

Number of installation packages of mobile banking trojans detected by Kaspersky, Q1 2019 – Q1 2020 (download)

Top 10 mobile banking trojans

  Verdict %*
1 Trojan-Banker.AndroidOS.Rotexy.e 13.11
2 Trojan-Banker.AndroidOS.Svpeng.q 10.25
3 Trojan-Banker.AndroidOS.Asacub.snt 7.64
4 Trojan-Banker.AndroidOS.Asacub.ce 6.31
5 Trojan-Banker.AndroidOS.Agent.eq 5.70
6 Trojan-Banker.AndroidOS.Anubis.san 4.68
7 Trojan-Banker.AndroidOS.Agent.ep 3.65
8 Trojan-Banker.AndroidOS.Asacub.a 3.50
9 3.00
10 2.70

* Unique users attacked by this malware as a percentage of all users of Kaspersky mobile products who were attacked by banking threats.

First and second places in our top 10 were claimed by trojans targeted at Russian-speaking mobile users: Trojan-Banker.AndroidOS.Rotexy.e (13.11%) and Trojan-Banker.AndroidOS.Svpeng.q (10.25%).

Third, fourth, eighth, and ninth positions in the top 10 mobile banking threats went to members of the Asacub family. The cybercriminals behind this trojan stopped creating new samples, but its distribution channels were still active in Q1.

Geography of mobile banking threats, Q1 2020 (download)

Top 10 countries by share of users attacked by mobile banking trojans

Country* %**
1 Japan 0.57
2 Spain 0.48
3 Italy 0.26
4 Bolivia 0.18
5 Russia 0.17
6 Turkey 0.13
7 Tajikistan 0.13
8 Brazil 0.11
9 Cuba 0.11
10 China 0.10

* Excluded from the rankings are countries with relatively few users of Kaspersky mobile products (under 10,000).
** Unique users attacked by mobile banking trojans as a percentage of all users of Kaspersky mobile products in the country.

In Q1 2020, Japan (0.57%) had the largest share of users attacked by mobile bankers; the vast majority of cases involved Trojan-Banker.AndroidOS.Agent.eq.

In second place came Spain (0.48%), where in more than half of all cases, we detected malware from the Trojan-Banker.AndroidOS.Cebruser family, and another quarter of detections were members of the Trojan-Banker.AndroidOS.Ginp family.

Third place belonged to Italy (0.26%), where, as in Spain, the Trojan-Banker.AndroidOS.Cebruser family was the most widespread with almost two-thirds of detections.

It is worth saying a bit more about the Cebruser family. Its creators were among the first to exploit the coronavirus topic to spread the malware.

When it runs, the trojan immediately gets down to business: it requests access to Accessibility Services to obtain Device Admin permissions, and then tries to get hold of card details.

The malware is distributed under the Malware-as-a-Service model; its set of functions is standard for such threats, but with one interesting detail — the use of a step-counter for activation so as to bypass dynamic analysis tools (sandbox). Cebruser targets the mobile apps of banks in various countries and popular non-financial apps; its main weapons are phishing windows and interception of two-factor authorization. In addition, the malware can block the screen using a ransomware tool and intercept keystrokes on the virtual keyboard.

Mobile ransomware trojans

In Q2 2020, we detected 4,339 installation packages of mobile trojan ransomware, 1,067 fewer than in the previous quarter.

Number of installation packages of mobile ransomware trojans detected by Kaspersky, Q1 2019 – Q1 2020 (download)

Top 10 mobile ransomware trojans

Verdict %*
1 Trojan-Ransom.AndroidOS.Svpeng.aj 17.08
2 Trojan-Ransom.AndroidOS.Congur.e 12.70
3 11.41
4 Trojan-Ransom.AndroidOS.Rkor.k 9.88
5 7.32
6 Trojan-Ransom.AndroidOS.Small.o 4.79
7 Trojan-Ransom.AndroidOS.Svpeng.aj 3.62
8 Trojan-Ransom.AndroidOS.Svpeng.ah 3.55
9 Trojan-Ransom.AndroidOS.Congur.e 3.32
10 Trojan-Ransom.AndroidOS.Fusob.h 3.17

* Unique users attacked by this malware as a percentage of all users of Kaspersky mobile products who were attacked by ransomware trojans.

Over the past few quarters, the number of ransomware trojans detected has been gradually decreasing; all the same, we continue to detect quite a few infection attempts by this class of threats. The main contributors to the statistics were the Svpeng, Congur, and Small ransomware families.

Geography of mobile ransomware trojans, Q1 2020 (download)

Top 10 countries by share of users attacked by mobile ransomware trojans:

Country* %**
1 USA 0.26
2 Kazakhstan 0.25
3 Iran 0.16
4 China 0.09
5 Saudi Arabia 0.08
6 Italy 0.03
7 Mexico 0.03
8 Canada 0.03
9 Indonesia 0.03
10 Switzerland 0.03

* Excluded from the rankings are countries with relatively few users of Kaspersky mobile products (under 10,000).
** Unique users attacked by mobile ransomware trojans as a percentage of all users of Kaspersky mobile products in the country.

The leaders by number of users attacked by mobile ransomware trojans are Syria (0.28%), the United States (0.26%) and Kazakhstan (0.25%)

Attacks on Apple macOS

In Q1 2020, we detected not only new versions of common threats, but one new backdoor family, whose first member was Backdoor.OSX.Capip.a. The malware’s operating principle is simple: it calls the C&C for a shell script, which it then downloads and executes.

Top 20 threats to macOS

Verdict %*
1 Trojan-Downloader.OSX.Shlayer.a 19.27
2 AdWare.OSX.Pirrit.j 10.34
3 AdWare.OSX.Cimpli.k 6.69
4 AdWare.OSX.Ketin.h 6.27
5 AdWare.OSX.Pirrit.aa 5.75
6 AdWare.OSX.Pirrit.o 5.74
7 AdWare.OSX.Pirrit.x 5.18
8 AdWare.OSX.Spc.a 4.56
9 AdWare.OSX.Cimpli.f 4.25
10 AdWare.OSX.Bnodlero.t 4.08
11 AdWare.OSX.Bnodlero.x 3.74
12 Hoax.OSX.SuperClean.gen 3.71
13 AdWare.OSX.Cimpli.h 3.37
14 AdWare.OSX.Pirrit.v 3.30
15 AdWare.OSX.Amc.c 2.98
16 AdWare.OSX.MacSearch.d 2.85
17 RiskTool.OSX.Spigot.a 2.84
18 AdWare.OSX.Pirrit.s 2.80
19 AdWare.OSX.Ketin.d 2.76
20 2.70

* Unique users attacked by this malware as a percentage of all users of Kaspersky security solutions for macOS who were attacked

The top 20 threats for macOS did not undergo any major changes in Q1 2020. The adware trojan Shlayer.a (19.27%) still tops the leaderboard, followed by objects that Shlayer itself loads into the infected system, in particular, numerous adware apps from the Pirrit family.

Interestingly, the unwanted program Hoax.OSX.SuperClean.gen landed in 12th place on the list. Like other Hoax-type programs, it is distributed under the guise of a system cleanup app, and immediately after installation, scares the user with problems purportedly found in the system, such as gigabytes of trash on the hard drive.

Threat geography

Country* %**
1 Spain 7.14
2 France 6.94
3 Italy 5.94
4 Canada 5.58
5 USA 5.49
6 Russia 5.10
7 India 4.88
8 Mexico 4.78
9 Brazil 4.65
10 Belgium 4.65

* Excluded from the rankings are countries with relatively few users of Kaspersky security solutions for macOS (under 5,000)
** Unique users who encountered macOS threats as a percentage of all users of Kaspersky security solutions for macOS in the country.

The leading countries, as in previous quarters, were Spain (7.14%), France (6.94%) and Italy (5.94%). The main contributors to the number of detections in these countries were the familiar Shlayer trojan and adware apps from the Pirrit family.

IoT attacks

IoT threat statistics

In Q1 2020, the share of IP addresses from which attempts were made to attack Kaspersky telnet traps increased significantly. Their share amounted to 81.1% of all IP addresses from which attacks were carried out, while SSH traps accounted for slightly less than 19%.

Distribution of attacked services by number of unique IP addresses of devices that carried out attacks, Q1 2020

It was a similar situation with control sessions: attackers often controlled infected traps via telnet.

Distribution of cybercriminal working sessions with Kaspersky traps, Q1 2020

Telnet-based attacks


Geography of device IP addresses where attacks at Kaspersky telnet traps originated, Q1 2020 (download)

Top 10 countries by location of devices from which attacks were carried out on Kaspersky telnet traps.

Country* %
China 13.04
Egypt 11.65
Brazil 11.33
Vietnam 7.38
Taiwan 6.18
Russia 4.38
Iran 3.96
India 3.14
Turkey 3.00
USA 2.57

For several quarters in a row, the leading country by number of attacking bots has been China: in Q1 2020 its share stood at 13.04%. As before, it is followed by Egypt (11.65%) and Brazil (11.33%).

SSH-based attacks


Geography of device IP addresses where attacks at Kaspersky SSH traps originated, Q1 2020 (download)

Top 10 countries by location of devices from which attacks were made on Kaspersky SSH traps.

Country* %
China 14.87
Vietnam 11.58
USA 7.03
Egypt 6.82
Brazil 5.79
Russia 4.66
India 4.16
Germany 3.64
Thailand 3.44
France 2.83

In Q1 2020, China (14.87%), Vietnam (11.58%) and the US (7.03%) made up the top three countries by number of unique IPs from which attacks on SSH traps originated.

Threats loaded into honeypots

Verdict %*
Trojan-Downloader.Linux.NyaDrop.b 64.35
Backdoor.Linux.Mirai.b 16.75 6.47
Backdoor.Linux.Gafgyt.a 4.36 1.30
Trojan-Downloader.Shell.Agent.p 0.68
Backdoor.Linux.Mirai.c 0.64
Backdoor.Linux.Hajime.b 0.46
Backdoor.Linux.Mirai.h 0.40
Backdoor.Linux.Gafgyt.av 0.35

* Share of malware type in the total amount of malware downloaded to IoT devices following a successful attack.

In Q1 2020, attackers most often downloaded the minimalistic trojan loader NyaDrop (64.35%), whose executable file does not exceed 500 KB. Threats from the Mirai family traditionally dominated: its members claimed four places in our top 10. These malicious programs will continue to rule the world of IoT threats for a long time to come, at least until the appearance of a more advanced (and publicly available) DDoS bot.

Financial threats

Financial threat statistics

In Q1 2020, Kaspersky solutions blocked attempts to launch one or several types of malware designed to steal money from bank accounts on the computers of 249,748 users.

Number of unique users attacked by financial malware, Q1 2020 (download)

Attack geography

To assess and compare the risk of being infected by banking trojans and ATM/POS malware in various countries, for each country we calculated the share of users of Kaspersky products that faced this threat during the reporting period out of all users of our products in that country.

Geography of banking malware attacks, Q1 2020 (download)

Top 10 countries by share of attacked users

Country* %**
1 Uzbekistan 10.5
2 Tajikistan 6.9
3 Turkmenistan 5.5
4 Afghanistan 5.1
5 Yemen 3.1
6 Kazakhstan 3.0
7 Guatemala 2.8
8 Syria 2.4
9 Sudan 2.1
10 Kyrgyzstan 2.1

* Excluded are countries with relatively few Kaspersky product users (under 10,000).
** Unique users whose computers were targeted by financial malware as a percentage of all unique users of Kaspersky products in the country.

Top 10 banking malware families

Name Verdicts %*
1 Emotet Backdoor.Win32.Emotet 21.3
2 Zbot Trojan.Win32.Zbot 20.8
3 CliptoShuffler Trojan-Banker.Win32.CliptoShuffler 17.2
4 RTM Trojan-Banker.Win32.RTM 12.3
5 Nimnul Virus.Win32.Nimnul 3.6
6 Trickster Trojan.Win32.Trickster 3.6
7 Neurevt Trojan.Win32.Neurevt 3.3
8 SpyEye Trojan-Spy.Win32.SpyEye 2.3
9 Danabot Trojan-Banker.Win32.Danabot 2.0
10 Nymaim Trojan.Win32.Nymaim 1.9

** Unique users attacked by this malware family as a percentage of all users attacked by financial malware.

Ransomware programs

Quarterly highlights

Ransomware attacks on organizations, as well as on city and municipal networks, did not ease off. Given how lucrative they are for cybercriminals, there is no reason why this trend of several years should cease.

More and more ransomware is starting to supplement encryption with data theft. To date, this tactic has been adopted by distributors of ransomware families, including Maze, REvil/Sodinokibi, DoppelPaymer and JSWorm/Nemty/Nefilim. If the victim refuses to pay the ransom for decryption (because, say, the data was recovered from a backup copy), the attackers threaten to put the stolen confidential information in the public domain. Such threats are sometimes empty, but not always: the authors of several ransomware programs have set up websites that do indeed publish the data of victim organizations.

Number of new modifications

In Q1 2020, we detected five new ransomware families and 5,225 new modifications of these malware programs.

Number of new ransomware modifications detected, Q1 2019 – Q1 2020 (download)

Number of users attacked by ransomware trojans

In Q1 2020, Kaspersky products and technologies protected 178,922 users from ransomware attacks.

Number of unique users attacked by ransomware trojans, Q1 2020 (download)

Attack geography


Geography of attacks by ransomware trojans, Q1 2020 (download)

Top 10 countries attacked by ransomware trojans

Country* %**
1 Bangladesh 6.64
2 Uzbekistan 1.98
3 Mozambique 1.77
4 Ethiopia 1.67
5 Nepal 1.34
6 Afghanistan 1.31
7 Egypt 1.21
8 Ghana 0.83
9 Azerbaijan 0.81
10 Serbia 0.74

* Excluded are countries with relatively few Kaspersky users (under 50,000).
** Unique users whose computers were attacked by ransomware trojans as a percentage of all unique users of Kaspersky products in the country.

Top 10 most common families of ransomware trojans

Name Verdicts %*
1 WannaCry Trojan-Ransom.Win32.Wanna 19.03
2 (generic verdict) Trojan-Ransom.Win32.Gen 16.71
3 (generic verdict) Trojan-Ransom.Win32.Phny 16.22
4 GandCrab Trojan-Ransom.Win32.GandCrypt 7.73
5 Stop Trojan-Ransom.Win32.Stop 6.62
6 (generic verdict) Trojan-Ransom.Win32.Encoder 4.28
7 (generic verdict) Trojan-Ransom.Win32.Crypren 4.15
8 PolyRansom/VirLock Virus.Win32.PolyRansom,


9 Crysis/Dharma Trojan-Ransom.Win32.Crusis 2.02
10 (generic verdict) Trojan-Ransom.Win32.Generic 1.56

* Unique Kaspersky users attacked by the specified family of ransomware trojans as a percentage of all users attacked by ransomware trojans.


Number of new modifications

In Q1 2020, Kaspersky solutions detected 192,036 new miner modifications.

Number of new miner modifications, Q1 2020 (download)

Number of users attacked by miners

In Q1, we detected attacks using miners on the computers of 518,857 unique users of Kaspersky Lab products worldwide.

Number of unique users attacked by miners, Q1 2020 (download)

Attack geography


Geography of miner attacks, Q1 2020 (download)

Top 10 countries attacked by miners

Country* %**
1 Afghanistan 6.72
2 Ethiopia 4.90
3 Tanzania 3.26
4 Sri Lanka 3.22
5 Uzbekistan 3.10
6 Rwanda 2.56
7 Vietnam 2.54
8 Kazakhstan 2.45
9 Mozambique 1.96
10 Pakistan 1.67

* Excluded are countries with relatively few users of Kaspersky products (under 50,000).
** Unique users whose computers were attacked by miners as a percentage of all unique users of Kaspersky products in the country.

Vulnerable applications used by cybercriminals during cyberattacks

We already noted that Microsoft Office vulnerabilities are the most common ones. Q1 2020 was no exception: the share of exploits for these vulnerabilities grew to 74.83%. The most popular vulnerability in Microsoft Office was CVE-2017-11882, which is related to a stack overflow error in the Equation Editor component. Hard on its heels was CVE-2017-8570, which is used to embed a malicious script in an OLE object inside an Office document. Several other vulnerabilities, such as CVE-2018-0802 and CVE-2017-8759, were also popular with attackers. In the absence of security updates for Microsoft Office, these vulnerabilities are successfully exploited and the user’s system becomes infected.

In second place were exploits for vulnerabilities in Internet browsers (11.06%). In Q1, cybercriminals attacked a whole host of browsers, including Microsoft Internet Explorer, Google Chrome, and Mozilla Firefox. What’s more, some of the vulnerabilities were used in APT attacks, such as CVE-2020-0674, which is associated with the incorrect handling of objects in memory in an outdated version of the JScript scripting engine in Internet Explorer, leading to code execution. Another example is the previously identified CVE-2019-17026, a data type mismatch vulnerability in Mozilla Firefox’s JIT compiler, which also leads to remote code execution. In the event of a successful attack, both browser exploits cause a malware infection. The researchers also detected a targeted attack against Google Chrome exploiting the RCE vulnerability CVE-2020-6418 in the JavaScript engine; in addition, the dangerous RCE vulnerability CVE-2020-0767 was detected in a component of the ChakraCore scripting engine used by Microsoft Edge. Although modern browsers have their own protection mechanisms, cybercriminals are forever finding ways around them, very often using chains of exploits to do so. Therefore, it is vital to keep the operating system and software up to date at all times.

Distribution of exploits used in attacks by type of application attacked, Q1 2020 (download)

This quarter, a wide range of critical vulnerabilities were detected in operating systems and their components.

  • CVE-2020-0601 is a vulnerability that exploits an error in the core cryptographic library of Windows, in a certificate validation algorithm that uses elliptic curves. This vulnerability enables the use of fake certificates that the system recognizes as legitimate.
  • CVE-2020-0729 is a vulnerability in processing LNK files in Windows, which allows remote code execution if the user opens a malicious shortcut.
  • CVE-2020-0688 is the result of a default configuration error in Microsoft Exchange Server, whereby the same cryptographic keys are used to sign and encrypt serialized ASP.NET ViewState data, enabling attackers to execute their own code on the server side with system rights.

Various network attacks on system services and network protocols were as popular as ever with attackers. We continue to detect attempts at exploiting vulnerabilities in the SMB protocol using EternalBlue, EternalRomance and similar sets of exploits. In Q1 2020, the new vulnerability CVE-2020-0796 (SMBGhost) was detected in the SMBv3 network protocol, leading to remote code execution, in which regard the attacker does not even need to know the username/password combination (since the error occurs before the authentication stage); however, it is present only in Windows 10. In Remote Desktop Gateway there were found two critical vulnerabilities (CVE-2020-0609 and CVE-2020-0610) enabling an unauthorized user to execute remote code in the target system. In addition, there were more frequent attempts to brute-force passwords to Remote Desktop Services and Microsoft SQL Server via the SMB protocol as well.

Attacks via web resources

The statistics in this section are based on Web Anti-Virus, which protects users when malicious objects are downloaded from malicious/infected web pages. Malicious websites are specially created by cybercriminals; web resources with user-created content (for example, forums), as well as hacked legitimate resources, can be infected.

Countries that are sources of web-based attacks: Top 10

The following statistics show the distribution by country of the sources of Internet attacks blocked by Kaspersky products on user computers (web pages with redirects to exploits, sites containing exploits and other malicious programs, botnet C&C centers, etc.). Any unique host could be the source of one or more web-based attacks.

To determine the geographical source of web-based attacks, domain names are matched against their actual domain IP addresses, and then the geographical location of a specific IP address (GEOIP) is established.

In Q1 2020, Kaspersky solutions defeated 726,536,269 attacks launched from online resources located in 203 countries worldwide. As many as 442,039,230 unique URLs were recognized as malicious by Web Anti-Virus components.

Distribution of web-based attack sources by country, Q1 2020 (download)

Countries where users faced the greatest risk of online infection

To assess the risk of online infection faced by users in different countries, for each country, we calculated the percentage of Kaspersky users on whose computers Web Anti-Virus was triggered during the quarter. The resulting data provides an indication of the aggressiveness of the environment in which computers operate in different countries.

This rating only includes attacks by malicious programs that fall under the Malware class; it does not include Web Anti-Virus detections of potentially dangerous or unwanted programs such as RiskTool or adware.

Country* % of attacked users**
1 Bulgaria 13.89
2 Tunisia 13.63
3 Algeria 13.15
4 Libya 12.05
5 Bangladesh 9.79
6 Greece 9.66
7 Latvia 9.64
8 Somalia 9.20
9 Philippines 9.11
10 Morocco 9.10
11 Albania 9.09
12 Taiwan, Province of China 9.04
13 Mongolia 9.02
14 Nepal 8.69
15 Indonesia 8.62
16 Egypt 8.61
17 Georgia 8.47
18 France 8.44
19 Palestine 8.34
20 Qatar 8.30

* Excluded are countries with relatively few Kaspersky users (under 10,000).
** Unique users targeted by Malware-class attacks as a percentage of all unique users of Kaspersky products in the country.

These statistics are based on detection verdicts returned by the Web Anti-Virus module that were received from users of Kaspersky products who consented to providing statistical data.

On average, 6.56% of Internet user’ computers worldwide experienced at least one Malware-class attack.

Geography of malicious web-based attacks, Q1 2020 (download)

Local threats

In this section, we analyze statistical data obtained from the OAS and ODS modules in Kaspersky products. It takes into account malicious programs that were found directly on users’ computers or removable media connected to computers (flash drives, camera memory cards, phones, external hard drives), or which initially made their way onto the computer in non-open form (for example, programs in complex installers, encrypted files, etc.).

In Q1 2020, our File Anti-Virus registered 164,653,290 malicious and potentially unwanted objects. 

Countries where users faced the highest risk of local infection

For each country, we calculated the percentage of Kaspersky product users on whose computers File Anti-Virus was triggered during the reporting period. These statistics reflect the level of personal-computer infection in different countries.

Note that this rating only includes attacks by malicious programs that fall under the Malware class; it does not include File Anti-Virus triggers in response to potentially dangerous or unwanted programs, such as RiskTool or adware.

Country* % of attacked users**
1 Afghanistan 52.20
2 Tajikistan 47.14
3 Uzbekistan 45.16
4 Ethiopia 45.06
5 Myanmar 43.14
6 Bangladesh 42.14
7 Kyrgyzstan 41.52
8 Yemen 40.88
9 China 40.67
10 Benin 40.21
11 Mongolia 39.58
12 Algeria 39.55
13 Laos 39.21
14 Burkina Faso 39.09
15 Malawi 38.42
16 Sudan 38.34
17 Rwanda 37.84
18 Iraq 37.82
19 Vietnam 37.42
20 Mauritania 37.26

* Excluded are countries with relatively few Kaspersky users (under 10,000).
** Unique users on whose computers Malware-class local threats were blocked as a percentage of all unique users of Kaspersky products in the country.

Geography of local infection attempts, Q1 2020 (download)

Overall, 19.16% of user computers globally faced at least one Malware-class local threat during Q1.

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Verizon’s 2020 DBIR | Securelist – 10 minute mail

Verizon’s 2020 DBIR is out, you can download a copy or peruse their publication online. Kaspersky was a contributor once again, and we are happy to provide generalized incident data from our unique and objective research.

We have contributed to this project and others like it for years now. This year’s ~120 page report analyses data from us and 80 other contributors from all over the world. The team provides thoughts on a mountain of breach data – “This year, we analyzed a record total of 157,525 incidents. Of those, 32,002 met our quality standards and 3,950 were confirmed data breaches”. And this year, Verizon pulled in far more data on cybercrime breaches this year, and report on thousands of them. We include a few interesting notes here.

  • 70% of reported breaches were perpetrated by external actors.
  • Majority of breaches do not just involve a dropped Trojan.
  • 86% of breaches were financially motivated.
  • 81% of breaches were contained in days or less.
  • Defenders are up against organized crime.
  • Almost a third of reported breaches involved ransomware.

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Maze Ransomware and its Various Campaigns Continue to Threaten the Cyber World – Disposable mail news

Ever since this year began, the Maze ransomware has been hitting headlines. Recently researchers discovered more samples of Maze in numerous industries making it one of the major threats for the cyber-world.

Another form of the “ChaCha” ransomware, Maze surfaced in mid-2019 and has been wreaking havoc ever since, across continents and any organization it could get it hands-on.

Per sources, Maze is most usually dispensed by way of emails loaded with malicious Exel and Word attachments. But that’s not the only method of distribution.

According to reports, cyber-criminals also use “exploit kits” by the name of “Spelevo”. Sources mention that in previous cases it has been used to exploit Flash Player vulnerabilities, CVE-2018-15982 and CVE-2018-4878. Other exploits that Maze has abused include CVE-2018-8174 (Internet Explorer) and CVE-2018-1150 (Pulse VPN).

Maze ransomware initially tries to get a strong idea of the target device’s internal surroundings and begins to create a place for itself. Once that’s done it tries to access user privileges to carry lateral movements and kick start the file encryption throughout drives. But, before the encryption, files are exfiltrated so as to be used for future compulsion in any way possible.

If the security system of a device isn’t laden with necessary protective gauges it could possibly crash completely under the pressure of Maze ransomware. The infection could put sensitive information at large and incapacitate operations almost killing the company’s finances.

Per sources, Maze ransomware has shown its hold across industries like construction, education, energy, finance, government, healthcare, hospitality, law, life sciences, media and communications, pharma, technology, and telecommunications. McAfee, in March, made available a detailed report about the Maze ransomware.

According to a report, there’s an “Anti-Ransomware Protection module” which hunts ransomware related encryption-based activities. It allows users to keep track of the activities.

Per sources, lately, Maze ransomware was spotted compromising several IT service providers. It also set up a footing in another victim device’s network via insecure Remote Desktop Protocol or by using brute-force on the account of the local administrator.
Cloud backups too aren’t safe from the Maze ransomware because they are widely tracked on the vulnerable networks. With the login credentials, all backed-up data could be sent to the threat-actors via a server under their control.

The solution for any such occurrences is as repetitive as ever; stronger security mechanisms, better passwords especially remote systems with remote access possibilities and of course, heftier protection measures.

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Attackers Exploit Two Vulnerabilities in SaltStack to Publish Arbitrary Control Messages and Much More – Disposable mail news

CISA has sent warnings to the users regarding two critical vulnerabilities in SaltStack Salt, an open-source remote task and configuration management framework that has been actively exploited by cybercriminals, leaving around thousands of cloud servers across the globe exposed to the threat.

The vulnerabilities that are easy to exploit are of high-severity and researchers have labeled them as particularly ‘dangerous’. It allows attackers to execute code remotely with root privileges on Salt master repositories to carry out a number of commands.

Salt is employed for the configuration, management, and monitoring of servers in cloud environments and data centers. It provides the power of automation as it scans IT systems to find vulnerabilities and then brings automation workflows to remediate them. It gathers real-time data about the state of all the aspects and it employs effective machine learning and industry expertise to examine threats more precisely. In a way, it is used to check installed package versions on all IT systems, look out for vulnerabilities, and then remediate them by installing fixes.

The two vulnerabilities, the first one called CVE-2020-11651 is an authentication bypass flaw and the other one CVE-2020-11652 is a directory transversal flaw, as per the discovery made by F-Secure researchers. The attackers can bypass all authentication and authorization controls by exploiting the vulnerabilities that would allow them to easily connect to the request server. Once the authentication is bypassed, attackers can post arbitrary control messages and make changes in the master server file system. All Salt versions prior to 2019.2.4 and 3000.2 are affected by the vulnerabilities.

Xen Orchestra, an effective all in one user-friendly web-based management service became the latest victim of cybercriminals involved in the exploitation of the two high-severity vulnerabilities in Salt. The attackers ran a cryptominer on the firm’s virtual machines (VMs), it has been noticed by the company on the 3rd of May as various services on their infrastructure became inaccessible.

While commenting on the matter, Olivier Lambert, Xen Orchestra’s founder, said, “A coin mining script ran on some of our VMs, and we were lucky nothing bad happened to us – no RPMs affected and no evidence that private customer data, passwords or other information have been compromised. GPG signing keys were not on any affected VMs. We don’t store any credit card information nor plain text credentials. Lesson learned…”

“In short, we were caught in a storm affecting a lot of people. We all have something in common: we underestimated the risk of having the Salt master accessible from outside,” he added. “Luckily, the initial attack payload was really dumb and not dangerous. We are aware it might have been far more dangerous and we take it seriously as a big warning. The malware world is evolving really fast: having an auto-update for our management software wasn’t enough.”

“If you are running SaltStack in your own infrastructure, please be very careful. Newer payloads could be far more dangerous,” warned Lambert.

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APT trends report Q1 2020 – 10 minute mail

For more than two years, the Global Research and Analysis Team (GReAT) at Kaspersky has been publishing quarterly summaries of advanced persistent threat (APT) activity. The summaries are based on our threat intelligence research and provide a representative snapshot of what we have published and discussed in greater detail in our private APT reports. They are designed to highlight the significant events and findings that we feel people should be aware of.

This is our latest installment, focusing on activities that we observed during Q1 2020.

Readers who would like to learn more about our intelligence reports or request more information on a specific report are encouraged to contact ‘[email protected]’.

Given the exceptional situation the world is living in because of the COVID-19 pandemia, it is mandatory we to start with a summary of how APT groups have been abusing this topic for different types of attacks.

COVID-19 APT activity

Since the World Health Organization (WHO) declared the COVID-19 a pandemic, this topic has received increased attention from different attackers. Many of the phishing scams we’ve seen have been launched by cybercriminals trying to cash-in on people’s fears about the virus.  However, the list of attackers also includes APT threat actors such as Kimsuky, APT27, Lazarus or ViciousPanda who, according to OSINT, have used COVID-19-themed lures to target their victims. We recently discovered a suspicious infrastructure that could have been used to target health and humanitarian organizations, including the WHO. Even though the infrastructure cannot be attributed to any particular actor at the moment, and was registered before the COVID-19 crisis in June 2019, according to some private sources it might be related to the DarkHotel actor. However, we cannot confirm this information at the moment. Interestingly, some groups have used the current situation to try to soften their reputation by declaring that they would not target health organizations during the crisis.

There are different publications reporting activity related to other APT actors using this lure, but in general, we do not believe this implies a meaningful change in terms of TTPs other than using a trendy topic for luring victims. We are closely monitoring the situation.

The most remarkable findings

In January 2020, we discovered a watering-hole utilizing a full remote iOS exploit chain. This site appears to have been designed to target users in Hong Kong, based on the content of the landing page. While the exploits currently being used are known, the actor responsible is actively modifying the exploit kit to target more iOS versions and devices. We observed the latest modifications on February 7. The project is broader than we initially thought, supporting an Android implant, and probably supporting implants for Windows, Linux, and MacOS. For the time being, we are calling this APT group TwoSail Junk. We believe this is a Chinese-speaking group; it maintains infrastructure mostly within Hong Kong, along with a couple of hosts located in Singapore and Shanghai. TwoSail Junk directs visitors to its exploit site by posting links within the threads of forum discussions, or creating new topic threads ofтtheir own. To date, dozens of visits were recorded from within Hong Kong, with a couple from Macau. The technical details around the functionality of the iOS implant, called LightSpy, and related infrastructure, reveal a low-to-mid capable actor. However, the iOS implant is a modular and exhaustively functional iOS surveillance framework.

Russian-speaking activity

In January, a couple of recently compiled SPLM/XAgent modules were detected in an Eastern European telecoms company. The initial point of entry is unknown, as is their lateral movement within this organization. It has become rare to identify SPLM infections, compared to past levels of Sofacy activity, so it seems that portions of this network may have been infected for some time. In addition to these SPLM modules, Sofacy also deployed .NET XTUNNEL variants and their loaders. These 20KB XTUNNEL samples themselves seem minimal in comparison to past XTUNNEL samples, which weighed in at 1-2MB. This shift to C# by the long-standing Sofacy XTunnel codebase reminds us of Zebrocy’s practice of re-coding and innovating long-used modules in multiple languages.

Gamaredon, a well-known APT group that has been active since at least 2013, has traditionally focused on Ukrainian entities. In recent months we have observed a campaign, made up of different waves, that has also been reported by multiple researchers on different social networks. The attackers sent malicious documents with remote template injection, resulting in a multi-level infection scheme to deploy a malicious loader that periodically contacts a remote C2 to download additional samples. Based on past research, we know that the Gamaredon’s toolkit includes many different malware artefacts, developed to achieve different goals. These include scanning drives for specific system files, capturing screenshots, executing remote commands, downloading additional files and managing the remote machine with programs such as UltraVNC. In this case, we observed an interesting new second stage payload that includes spreading capabilities, that we call “Aversome infector”. This malware seems to have been developed to maintain a strong persistence in the target network and to move laterally by infecting Microsoft Word and Excel documents on external drives.

Chinese-speaking activity

CactusPete is a Chinese-speaking cyber-espionage group active since at least 2012 characterized by medium-level technical capabilities. Historically, this threat actor has targeted organizations within a limited range of countries – South Korea, Japan, the US and Taiwan. At the end of 2019 the group seemed to shift towards a heavier focus on Mongolian and Russian organizations. CactusPete offensive activity against the Russian defense industry and Mongolian government appears to be mostly delineated from its Russian-Mongolian commercial and border relationships. However, one bait exploit document dropping its Flapjack backdoor (tmplogon.exe, primarily focused on new Russian targets) is authored in Mongolian. The group’s broadening of techniques, exploit re-purposing, targeting shift and possible expansion suggests changes in the group’s resources and operations.

Rancor is a group that has been publicly reported since 2018, with connections to DragonOK. This actor traditionally had a focus on Southeast Asian targets, namely Cambodia, Vietnam and Singapore. We noted several updates to the group’s activity in the last few months, namely the discovery of a new variant of the Dudell malware that we are calling ExDudell, a new tool for bypassing UAC (User Account Control), and new infrastructure utilized in the attacks. Apart from this, we have also identified that the initial lure documents that were previously sent via mail, are now found in the Telegram Desktop directory, suggesting the group is possibly making a shift in its initial delivery method.

In 2019, we detected activity by an unknown actor at the time deploying watering holes on websites representing Tibetan interests, fooling victims into installing fake Adobe Flash updates hosted on a GitHub repository. Kaspersky thwarted the attack by coordinating a takedown of this repository with GitHub. After a brief period of inactivity, we detected a new round of watering holes featuring a renewed toolset. We decided to call the group behind this activity Holy Water.

The threat actor’s unsophisticated but creative toolset has been evolving a lot since the inception date, may still be in development, and leverages Sojson obfuscation, NSIS installer, Python, open-source code, GitHub distribution, Go language, as well as Google Drive-based C2 channels.

Middle East

We recently detected a new, ongoing data exfiltration campaign targeting victims in Turkey that started in February 2020. While StrongPity’s TTPs in terms of targeting, infrastructure and infection vector haven’t changed, we observed a somewhat peculiar change in the documents they attempt to exfiltrate. In this campaign, StrongPity updated its latest signature backdoor, named StrongPity2, and added more files to exfiltrate to its list of common Office and PDF documents, including Dagesh Pro Word Processor files used for Hebrew dotting, RiverCAD files used for river flow and bridge modelling, plain-text files, archives as well as GPG encrypted files and PGP keys.

In March, we discovered a targeted campaign to distribute Milum, a Trojan designed to gain remote control of devices in target organizations, some of which operate in the industrial sector. The first signs of this operation, which we have dubbed WildPressure, can be traced back to August 2019; still, the campaign remains active. The Milum samples we have seen so far do not share any code similarities with any known APT campaigns. The malware provides attackers with remote control over infected devices, allows downloading and executing commands, collecting and exfiltrating information and installing upgrades in the malware.

In late December 2019, Kaspersky Threat Attribution Engine detected a new variant of the Zerocleare wiper that had possibly been used in targeted attacks on energy sector targets in Saudi Arabia. This quarter, we identified a new variant of this wiper, called Dustman. It is similar to Zerocleare in terms of wiping and distribution, but changes in variables and technical names suggest this might have been in readiness for a new wave of attacks specifically targeting Saudi Arabia’s energy sector, based on messages embedded in the malware and the mutex created by it. The PDB file of the Dustman wiper suggested that this destructive code was the release edition and was ready for deployment in a target network. These changes coincided with the New Year holidays, during which many employees take time off to celebrate. Shamoon was delivered with similar timing in 2012 during Ramadan celebrations.

Southеast Asia and Korean Peninsula

A Lazarus campaign outlined by the Italian security company Telsy in November 2019 allowed us to find a connection to previous activity from the group targeting cryptocurrency businesses. The malware mentioned on Telsy’s blog is a first stage downloader that has been observed since mid-2018. We found that the second stage malware is a variant of Manuscrypt, uniquely attributed to Lazarus, deploying two types of payloads. The first is a manipulated Ultra VNC program, and the second is a multi-stage backdoor. This type of multi-stage infection procedure is typical of the Lazarus group’s malware, especially when using the Manuscrypt variant. In this campaign, our telemetry indicates that the Lazarus group attacked cryptocurrency businesses in Cyprus, the US, Taiwan and Hong Kong, and the campaign extended until the beginning of 2020.

Kimsuky, an actor we have been tracking since 2013, was especially active during 2019. In December, Microsoft took down 50 domains used by the group and filed a lawsuit against the attackers in a Virginia court. However, the group has continued its activity without significant changes. We recently discovered a new campaign where the actor used a decoy image themed around New Year’s greetings that delivers its old downloader with a new evolved next-stage payload designed to steal information that uses a new encryption method.

At the end of January, we stumbled upon a malicious script exploiting an Internet Explorer vulnerability, CVE-2019-1367. After closely examining the payload and finding connections with previous activity, we concluded that DarkHotel was behind this campaign, probably in progress since 2018. The campaign saw DarkHotel utilize a multi-stage binary infection phase using home-brewed malware. The initial infection creates a downloader which fetches another downloader to collect system information and fetch the final backdoor only for high-value victims. DarkHotel used a unique combination of TTPs in this campaign. The threat actor used diverse infrastructure to host malware and to control infected victims, including a compromised web server, a commercial hosting service, a free hosting service and a free source code tracking system. We were able to confirm targeted companies in South Korea and Japan in this campaign.

In March, researchers from Google revealed that a group of hackers used five zero-days to target North Koreans and North Korean-focused professionals in 2019. The group exploited flaws in Internet Explorer, Chrome, and Windows with phishing emails that carried malicious attachments or links to malicious sites, as well as watering-hole attacks. We were able to match two of the vulnerabilities – one in IE and one in Windows – to DarkHotel.

FunnyDream is a campaign that started in mid-2018, targeting high-profile entities in Malaysia, Taiwan and the Philippines, with the majority of victims in Vietnam. Our analysis revealed that it’s part of a wider campaign that stretches back a few years and targets governments, and specifically foreign organizations, of countries in Southeast Asia. The attacker’s backdoor downloads and uploads files from/to a C2, executes commands and runs new processes in the victim. It also collects information about other hosts on the network and is delivered to new hosts through remote execution utilities. The attacker also used an RTL backdoor and Chinoxy backdoor. The C2 infrastructure has been active since mid-2018 and domains show an overlap with the FFRAT malware family. In a number of cases, indications suggest the backdoor was delivered via a previous long-term compromise. The campaign is still active.

Operation AppleJeus was one of the more notable campaigns of Lazarus, and the first time the actor targeted macOS targets. Our January follow-up research revealed significant changes to the group’s attack methodology: homemade macOS malware and an authentication mechanism to carefully deliver the next-stage payload, as well as loading the next-stage payload without touching the disk. To attack Windows victims, the group has elaborated a multi-stage infection procedure and significantly changed the final payload. We believe that Lazarus has been more careful in its attacks since the release of Operation AppleJeus and has employed a number of methods to avoid detection. We identified several victims in the UK, Poland, Russia and China. Moreover, we were able to confirm that several of the victims are linked to cryptocurrency organizations.

Roaming Mantis is a financially motivated actor first reported in 2017, when it used SMS to distribute its malware to Android devices based in South Korea. Since then, the scope of the group’s activities has widened considerably, supporting 27 languages, targeting iOS as well as Android, and even mining cryptocurrency. The actor also added new malware families, including Fakecop and Wroba.j to its arsenal, and is still active using ‘SMiShing‘ for Android malware distribution. In a recent campaign it distributed malicious APKs masquerading as popular couriers and customized for the targeted countries, including Japan, Taiwan, South Korea and Russia.

Other interesting discoveries

TransparentTribe started using a new module named USBWorm at the beginning of 2019, as well as improving its custom .NET tool named CrimsonRAT. Based on our telemetry, USBWorm was used to infect thousands of victims, most of them located in Afghanistan and India, providing the attacker with the ability to download and execute arbitrary files, spread to removable devices and steal files of interest from infected hosts even those disconnected from the internet. As we previously reported, this group mainly focuses on military targets, which are usually compromised with Office documents armed with malicious VBA and open-source malware like Peppy RAT and CrimsonRAT. In its new campaign, which is still active, we noticed the group’s focus shift more towards targeting entities located in Afghanistan in addition to India. Transparent Tribe has also developed a new implant designed to infect Android devices, a modified version of the AhMyth Android RAT which is open source malware available on GitHub.

During the last months of 2019, we observed an ongoing campaign conducted by Fishing Elephant. The group continues to use both Heroku and Dropbox in order to deliver its tool of choice, AresRAT. We discovered that the actor incorporated a new technique into its operations that is meant to hinder manual and automatic analysis – geo-fencing and hiding executables within certificate files. During our research, we also detected a change in victimology that may reflect the current interests of the threat actor: the group is targeting government and diplomatic entities in Turkey, Pakistan, Bangladesh, Ukraine and China.

Final thoughts

While the threat landscape isn’t always full of “groundbreaking” events, when we cast our eyes back over the activities of APT threat actors, there are always interesting developments.  Our regular quarterly reviews are intended to highlight the key developments.

These are some of the main trends that we’ve seen this year so far.

  • It’s clear from the activities of various APT groups, including CactusPete, LightSpy, Rancor, Holy Water, TwoSail Junk and others that geo-politics continues to be an important driver of APT activity. This was also underlined this quarter by the UK National Cyber Security Centre laying responsibility for disruptive attacks on Georgia at the feet of Russia’s military intelligence service, indictments in the US of two Chinese nationals for laundering $100 million in cryptocurrency on behalf of North Korea and the alleged ‘catfishing’ of IDF soldiers by Hamas.
  • Financial gain remains a motive for some threat actors, as evidenced by the activities of Lazarus and Roaming Mantis.
  • Southeast Asia is the most active region in terms of APT activities, including established actors such as Lazarus, DarkHotel and Kimsuky, and newer groups such as Cloud Snooper and Fishing Elephant.
  • APT threat actors such as CactusPete, TwoSail Junk, FunnyDream, DarkHotel continue to exploit software vulnerabilities.
  • APT threat actors continue to include mobile implants in their arsenal.
  • APT threat actors such as (but not limited to) Kimsuky, Hades and DarkHotel, as well as opportunistic criminals, are exploiting the COVID-19 pandemic.

All in all, we see the continuous growth of activity in Asia and how some of the actors we called newcomers are now well established. On the other hand, the more traditional advanced actors seem to be more and more selective in their operations, probably following a change of paradigm. The use of mobile platforms for infections and the distribution of malware is on the rise. Every actor seems to have some artefacts for these platforms and in some campaigns they are the main target.

COVID-19 is clearly top of everyone’s minds at the moment and APT threat actors have also been seeking to exploit this topic in spear-phishing campaigns.  We do not believe this represents a meaningful change in terms of TTPs: they’re simply using it as a newsworthy topic to lure their victims. However, we are closely monitoring the situation.

As always, we would note that our reports are the product of our visibility into the threat landscape. However, it should be borne in mind that, while we strive to continually improve, there is always the possibility that other sophisticated attacks may fly under our radar.

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Google Confirm Two New High-Severity Vulnerabilities in Chrome 81 – Disposable mail news

The new Chrome 81 version released on April 7th by Google for Windows, Mac, and Linux primarily focused on security owing to the vulnerability users are subjected to due to the coronavirus pandemic. The launch of the update was delayed for similar reasons. It brought along new features, bug fixes, and over 30 security flaw patches from Google’s security researchers and some experts from outside.

The new Chrome 81 version is being promoted to the Stable channel, meanwhile, Chrome 83 and Chrome 84 will be promoted to the Beta version and the Canary version respectively. As per sources, Chrome 82 will be disregarded because of the COVID-19 charged atmosphere, and all progress from the version will be channelized into the subsequent version, Chrome 83.

While warning users of more security flaws in Chrome 81, Google confirms two new high-severity vulnerabilities infecting the web browser. As these new security exploits could allow hackers to run commands over an affected system by gaining unauthorized control, users worldwide are being advised by the U.S Cybersecurity and Infrastructure Security Agency (CISA) to apply the latest update launched by the company in defense against these security vulnerabilities.

Both of the aforementioned security vulnerabilities were reported by Zhe Jin from Qihoo 360, a Chinese internet security services provider; for one of these, Jin received a bounty of $10,000 for CVE-2020-6462 which is a use-after-free error in the Chrome task scheduling component. The second one, CVE-2020-6461 was also of a similar use-after-free form but this one affected storage, according to the update notice from Prudhvikumar Bommana, Google Chome Technical Program Manager. 

Google has confirmed that the update will be pushed for all the users in the upcoming days and weeks, however, users are advised to remain proactive and keep looking up for updates to be applied manually by going to Help | About Google Chrome, where you can find the version you are currently running and an option to check for further updates. After installing the latest version, simply restart the web browser, and there you go being safeguarded against both the flaws.

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CERT-In Alerts Mozilla Firefox Users to Update their Browsers Immediately – Disposable mail news

Mozilla Firefox users are receiving alerts regarding multiple vulnerabilities in the web browser by the Indian Computer Emergency Response Team (CERT-In). An advisory has also been issued in the regard asking the users to update their web browsers as soon as possible.

While rating the severity of the vulnerability as ‘High’ on all the versions of Mozilla Firefox that have been released before version 75 and version 68.7 on Mozilla Firefox ESR, the CERT-In stated in the advisory that remote hackers can take advantage of these browser flaws to acquire sensitive data through the browser.

According to the CERT-In advisory, “Out-of-Bounds Read Vulnerability in Mozilla Firefox ( CVE-2020-6821 ). This vulnerability exists in Mozilla Firefox due to a boundary condition when using the WebGLcopyTexSubImage method. A remote attacker could exploit this vulnerability by specially crafted web pages. Successful exploitation of this vulnerability could allow a remote attacker to disclose sensitive information,”

“Information Disclosure Vulnerability in Mozilla Firefox ( CVE-2020-6824). This vulnerability exists in Mozilla Firefox to generate a password for a site but leaves Firefox open.A  remote attacker could exploit this vulnerability by revisiting the same site of the victim and generating a new password. The generated password will remain the same on the targeted system,” the advisory further reads.

The aforementioned vulnerability also allows the attacker to execute ‘arbitrary code’ on the targeted system, letting them run any chosen command onto it. As per sources, another flaw was also found to be existing in the internet browser that concerns with a boundary condition in GMP Decode Data as images exceeding 4GB are being processed on 32-bit builds. The exploitation of this flaw requires the attacker to trick users into opening specially designed images. Upon successful exploitation, the attacker can yet again execute arbitrary code on the targeted system.

Another way by which a remote attacker can take advantage of this exploit is by convincing a user to install a crafted extension, on doing so the attacker will be able to obtain sensitive information.

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Biometric Data Exposure Vulnerability in OnePlus 7 Pro Android Phones Highlighted TEE Issues – Disposable mail news

In July 2019, London based Synopsys Cybersecurity Research Center discovered a vulnerability in OnePlus 7 Pro devices manufactured by Chinese smartphone maker OnePlus. The flaw that could have been exploited by hackers to obtain users’ fingerprints was patched by the company with a firmware update it pushed in the month of January this year. As per the findings, the flaw wasn’t an easy one to be exploited but researchers pointed out the possibility of a bigger threat in regard to TEEs and TAs.

Synopsys CyRC’s analysis of the vulnerability referred as CV toE-2020-7958, states that it could have resulted in the exposure of OnePlus 7 pro users’ biometric data. The critical flaw would have allowed authors behind malicious android applications with root privileges to obtain users’ bitmap fingerprint images from the device’s Trusted Execution Environment (TEE), a technique designed to protect sensitive user information by keeping the Android device’s content secure against illicit access.

As it has become increasingly complex for malicious applications to acquire root privileges on Android devices, the exploitation of the flaw would have been an arduous task and might also be an unlikely one given the complexity of the successful execution. Meanwhile, the fix has been made available for months now–
ensuring the protection of the users.

However, the issue with Trusted Execution Environments (TEEs) and Trusted Applications (TAs) remains the major highlight of Synopsys’s advisory released on Tuesday, “Upon obtaining root privileges in the REE [Rich Execution Environment], it becomes possible to directly communicate with the factory testing APIs exposed by Trusted Applications (TAs) running in the TEE. This attacker invokes a sequence of commands to obtain raw fingerprint images in the REE,” it read.

While explaining the matter, Travis Biehn, principal consultant at Synopsys, told, “Of course, people’s fingerprints don’t usually change. As attackers become successful in retrieving and building large datasets of people’s fingerprints, the usefulness of naïve fingerprint recognition in any application as a security control is permanently diminished,”

“A further possible consequence is that fingerprints become less trustworthy as evidence in our justice systems.”

“…this vulnerability shows that there’there are challenges with Trusted Execution Environments (TEEs) and Trusted Applications (TAs); these are software components that are opaque to most (by design), expertise is limited, and typically involve long supply chains. These factors together mean there’there are opportunities for organizations to make a mistake, and hard for security experts to catch at the right time,” he further added.

The flaw would have allowed attackers to recreate the targeted user’s complete fingerprint and then use it to generate a counterfeit fingerprint that further would have assisted them in accessing other devices relying upon biometric authentication.

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YARA webinar follow up | Securelist – 10 minute mail

If you read my previous blogpost, “Hunting APTs with YARA” then you probably know about the webinar we’ve done on March 31, 2020, showcasing some of our experience in developing and using YARA rules for malware hunting.

In case you’ve missed the webinar or if you attended and want to re-watch it, you can find the recording here:

As requested by many of you, we are also making the slides available through SlideShare:

Unfortunately, we were forced to cut short the broadcast as we were running out of time. Nevertheless, we received a number of interesting questions and as I promised, I will try to answer them below. Thanks to everyone who participated and appreciate all the feedback and ideas!

YARA webinar – questions

  1. Can you share the presentation? (multiple)

    Sure, please find the link above for SlideShare.

  2. Hi Costin! what is the point of writing a rule on the exploit and not about the vulnerability? (from Ari)

    Hi Ari, hope you guys are doing well! In this case, we are trying to hunt an unknown 0day exploit, therefore, we don’t know which vulnerability it exploits. The only thing we can try to hunt for are the artifacts that the exploit developer left in his older exploits of the same kind (in this case, Silverlight). For more details, please see our blogpost: The mysterious case of CVE-2016-0034: the hunt for a Microsoft Silverlight 0-day.

  3. I’ll add an xml-based switch to show Imphash in lowercase, in pestudio! (from Marc)

    Thanks Marc, appreciated, and sorry for mispronouncing your last name! Everyone, in case you aren’t already using Pestudio for your initial malware assessment, go check it out.

  4. “Your italian is pretty good man / your italian is not so bad / Your italian is great 🙂 ” – various amici

    Thank you! Perhaps not surprisingly, Romania used to be a Roman colony 2000 years ago, which is why our languages are so similar. Wishing you guys all the best, stay safe and stay healthy!

  5. When you are looking or other languages, does the “pe.language” catch all hexbyte formats? (I.e. UTF-8 and UTF-16 will show mandarin characters in different hex bytes) (from Jono)

    That’s a good question. In reality, pe.language actually cycles through all the resources in the PE file and returns true if the language of at least one resource matches the one you are looking for. So it doesn’t really searching for any characters in the file, only using the metadata from the resource section.

  6. Can please explain “not for all i” in criteria – from Rohit, referring to the generic YARA rule from example 3
    Indeed, this is one tricky rule. Just to make it easier, I’m showing the solution below:

    In essence, the rule works as follows: first, the version_info structure field named “CompanyName” should contain “Microsoft”, which means the file is claiming to be from Microsoft. Secondly, it needs to be signed with a digital certificate, so pe.number_of_signatures should be larger than 0. Finally, we check if there is at least one issuer for all the certificates used to sign the file that is not Microsoft nor VeriSign. Why “not for all”? Well, it’s a reverse logic – for all the certificates, we want to make sure the signatures are either from Microsoft or VeriSign. If at least one sig is found that is not from these two, the file is suspicious. Another way to do this would be to keep “and for all” and apply the not inside the loop, switching the “or” for an “and”. (because not (a or b) ==not a and not b)

  7. Do you have any open source database of good and benign files to test against false positives? (from Ramon)

    Hey Ramon, thanks for the question! Please turn to slide 37 for advice on how to build a benign sample set for QA and false positives testing.

  8. When you specify the “filesize” attribute within your rule – what denomination do you target? Bytes, Kilobytes, Megabytes etc…? (from James)

    By default, the filesize is expressed in bytes, so 200000 would be 200000 bytes. The YARA syntax also supports KB and MB, with KB multiplying by 1024 and MB by 2^.20.

  9. Would you recommend using the xor modifier now for this stuff? (from John) referring to slide 39:

    In particular, the example on the right side is from Shamoon2 samples, where some of the strings would be XOR’ed by a one byte key which kept changing from sample to sample. Interesting enough, YARA supports the “xor” modifier, since version 3.8 (or so). However, the xor modifier is always applied last, so for our case above, it would work, as the zeroes in the wide strings would be xor’ed as well! Therefore, we need to bruteforce the strings and use them like in the case above, if zeroes are not xor’ed.

  10. How long does it take to scan your full collection with a normal YARA rule? (from Juan Aleister-Crowley)

    The entire Kaspersky malware collection, which is possibly one of the largest in the world, takes between 1 and 2 weeks to scan entirely, on a cluster of a few hundred computers. However, in most case, we resort to scanning subsets, such as recent samples or known APT samples already tagged by our robots, which takes between minutes and up to a day or two.

  11. What is your experience of using matching on the PE Rich Header? (from Axel)

    Good question! While in theory the pe module could allow for creation of rules that match on the decrypted Rich header, we haven’t played much with that. This is however something we’ve explored in connection to the Hades APT attack on the Winter Olympics and the associated false flag that relied on the Rich header from a Lazarus sample.

  12. What are some best practices around managing a collection of YARA rules? Rules harvested from the web as well as the ones internally developed. Are there any specific tools dedicated to maintaining such a collection? Do you just use Git? (from V)

    Hey V, thanks for the question! This is indeed one of the trickiest things and I have to admit that I do not know of a perfect solution yet. Indeed, there are some YARA management frameworks, but I can’t say I’m a big fan of any of them in particular. I do use Git for this purpose, but I also lack a nice visual interface that would allow me to search, edit and run them against samples with a click.

  13. Better speed if checking the file size before the rules? (from Damien)

    That’s a good question. According to Victor, the condition is evaluated by a decision tree, so the order is not necessarily the one that you put in the syntax. To be honest, I do prefer to put the filesize check first, perhaps for “superstition” reasons 🙂

  14. Here is a question “5 of ($b*)” means “any 5 of ($b*)” or “first 5 of ($b*)” (from Yerbol)

    Indeed, that means any (sub-)group of five $b strings.

  15. Hi, why is important and good indicator to use PDB paths in a YARA sigs? (from Adrian)

    Based on our experience, PDB paths, in particular unique looking folder names from PDB paths, are very good for detection of future malware from the same author. For example, taking an EternalBlue scanner from Omerez, that is used by the CobaltGoblin group, it has the following PDB inside:
    C:OmerezProjectsEternal BluesEternalBlueScannerobjReleaseEternalBlues.pdb
    A YARA rule that matches on “C:OmerezProjects” could find other tools from the same author.

If you have more questions about the YARA webinar, please feel free to drop us a line in the comments box below or on Twitter: @craiu.

P.S. Special note for those trying to do the iOS/MacOS homework – if you write the rules but don’t have access to a platform to run them for hunting purposes, please drop us a note at: yarawebinar [at]

Thanks and stay safe!

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