je internetový portál zaměřený na počítačovou bezpečnost, hacking, anonymitu, počítačové sítě, programování, šifrování, exploity, Linux a BSD systémy. Provozuje spoustu zajímavých služeb a podporuje příznivce v zajímavých projektech.


Microsoft Adds Default Protection Against RDP Brute-Force Attacks in Windows 11

The Hacker News - 25 Červenec, 2022 - 17:43
Microsoft is now taking steps to prevent Remote Desktop Protocol (RDP) brute-force attacks as part of the latest builds for the Windows 11 operating system in an attempt to raise the security baseline to meet the evolving threat landscape. To that end, the default policy for Windows 11 builds – particularly, Insider Preview builds 22528.1000 and newer – will automatically lock accounts for 10 Ravie Lakshmanan
Kategorie: Hacking & Security

Experts Uncover New 'CosmicStrand' UEFI Firmware Rootkit Used by Chinese Hackers

The Hacker News - 25 Červenec, 2022 - 16:05
An unknown Chinese-speaking threat actor has been attributed to a new kind of sophisticated Unified Extensible Firmware Interface (UEFI) firmware rootkit called CosmicStrand. "The rootkit is located in the firmware images of Gigabyte or ASUS motherboards, and we noticed that all these images are related to designs using the H81 chipset," Kaspersky researchers said in a new report published todayRavie Lakshmanan
Kategorie: Hacking & Security

3 Distros for Linux Newcomers Who Just Want to Get Work Done - 25 Červenec, 2022 - 13:00
If you're a casual user who just wants a secure, reliable OS that helps you be more productive, here are some top distro recommendations.
Kategorie: Hacking & Security

Practical Guide to Using End-to-end Encryption (E2EE) on Linux - 25 Červenec, 2022 - 13:00
End-to-end encryption is an increasingly popular method that online services are using to ensure their users' security. End-to-end encryption, also known as E2EE, encodes messages sent from one user to another in a way that ensures that only the sender and recipient can decode the message.
Kategorie: Hacking & Security

Why Physical Security Maintenance Should Never Be an Afterthought

Threatpost - 25 Červenec, 2022 - 13:00
SecuriThings' CEO Roy Dagan tackles the sometimes overlooked security step of physical security maintenance and breaks down why it is important.
Kategorie: Hacking & Security

CosmicStrand: the discovery of a sophisticated UEFI firmware rootkit

Kaspersky Securelist - 25 Červenec, 2022 - 12:00


Rootkits are malware implants which burrow themselves in the deepest corners of the operating system. Although on paper they may seem attractive to attackers, creating them poses significant technical challenges and the slightest programming error has the potential to completely crash the victim machine. In our APT predictions for 2022, we noted that despite these risks, we expected more attackers to reach the sophistication level required to develop such tools. One of the main draws towards malware nested in such low levels of the operating system is that it is extremely difficult to detect and, in the case of firmware rootkits, will ensure a computer remains in an infected state even if the operating system is reinstalled or the user replaces the machine’s hard drive entirely.

In this report, we present a UEFI firmware rootkit that we called CosmicStrand and attribute to an unknown Chinese-speaking threat actor. One of our industry partners, Qihoo360, published a blog post about an early variant of this malware family in 2017.

Affected devices

Although we were unable to discover how the victim machines were infected initially, an analysis of their hardware sheds light on the devices that CosmicStrand can infect. The rootkit is located in the firmware images of Gigabyte or ASUS motherboards, and we noticed that all these images are related to designs using the H81 chipset. This suggests that a common vulnerability may exist that allowed the attackers to inject their rootkit into the firmware’s image.

In these firmware images, modifications have been introduced into the CSMCORE DXE driver, whose entry point has been patched to redirect to code added in the .reloc section. This code, executed during system startup, triggers a long execution chain which results in the download and deployment of a malicious component inside Windows.

Looking at the various firmware images we were able to obtain, we assess that the modifications may have been performed with an automated patcher. If so, it would follow that the attackers had prior access to the victim’s computer in order to extract, modify and overwrite the motherboard’s firmware. This could be achieved through a precursor malware implant already deployed on the computer or physical access (i.e., an evil maid attack scenario). Qihoo’s initial report indicates that a buyer might have received a backdoored motherboard after placing an order at a second-hand reseller. We were unable to confirm this information.

Overview of the infection process

Before getting into the various components that compose this rootkit, we would like to provide a high-level view of what it tries to accomplish. The goal of this execution chain is to deploy a kernel-level implant into a Windows system every time it boots, starting from an infected UEFI component.

UEFI malware authors face a unique technical challenge: their implant starts running so early in the boot process that the operating system (in this case Windows) is not even loaded in memory yet – and by the time it is, the UEFI execution context will have terminated. Finding a way to pass down malicious code all the way through the various startup phases is the main task that the rootkit accomplishes.

The workflow consists in setting hooks[1] in succession, allowing the malicious code to persist until after the OS has started up. The steps involved are:

  • The initial infected firmware bootstraps the whole chain.
  • The malware sets up a malicious hook in the boot manager, allowing it to modify Windows’ kernel loader before it is executed.
  • By tampering with the OS loader, the attackers are able to set up another hook in a function of the Windows kernel.
  • When that function is later called during the normal start-up procedure of the OS, the malware takes control of the execution flow one last time.
  • It deploys a shellcode in memory and contacts the C2 server to retrieve the actual malicious payload to run on the victim’s machine.

These steps are summed up in the following graph:

UEFI implant – detailed analysis MD5 DDFE44F87FAC7DAEEB1B681DEA3300E9 SHA1 9A7291FC90F56D8C46CC78397A6F36BB23C60F66 SHA256 951F74882C1873BFE56E0BFF225E3CD5D8964AF4F7334182BC1BF0EC9E987A0A Link time Wednesday, 12.08.2015 12:17:57 UTC File type EFI Boot Service DXE Driver File size 96.84 KB GUID A062CF1F-8473-4AA3-8793-600BC4FFE9A8 (CSMCORE)

Having established what the malware implant tries to accomplish, we can now look into more detail at how each of these steps is performed.

  1. The whole execution chain begins with an EFI driver. It appears to be a patched version of a legitimate one named CSMCORE (intended to facilitate the boot of the machine in legacy mode via the MBR), where the attackers have modified the pointer to the HandleProtocol boot service function. Every time this function is called, the execution is redirected to attacker-supplied code that tries to determine which component called it (it is looking for a specific one to infect – efi). By examining the function arguments as well as the bytes located at the return address, CosmicStrand can identify the exact “call” it is looking for.

  2. This specific point in the execution was chosen because at this stage the boot manager is loaded in memory, but isn’t yet running. CosmicStrand seizes this chance to patch a number of bytes in its Archpx64TransferTo64BitApplicationAsm
  3. That function is later called during the normal OS startup process, also at a strategic time: by then the Windows OS loader is also present in memory and can in turn be modified.
  4. When it runs, Archpx64TransferTo64BitApplicationAsm locates a function from the OS loader (OslArchTransferToKernel) by looking for a specific byte pattern. CosmicStrand then adds a hook at the very end of it.

  5. OslArchTransferToKernel is called just before execution is transferred from the Windows loader to the Windows kernel, which makes it a traditional hooking point for rootkits of that sort.
  6. Before the Windows kernel has had a chance to run, CosmicStrand sets up yet another hook in the ZwCreateSection Malicious code is copied[2] into the image of ntoskrnl.exe in memory, and the first bytes of ZwCreateSection are overwritten to redirect to it. We note that the attackers were careful to place the malicious code inside the slack space of ntoskrnl.exe’s .text section, which makes this redirection a lot less conspicuous in the eyes of possible security products.

    At this point, CosmicStrand also seemingly attempts to disable PatchGuard, a security mechanism introduced to prevent modifications in key structures of the Windows kernel in memory. To do so, it locates ntoskrnl.exe’s KiFilterFiberContext function[3] and modifies it so it returns without performing any work. It is worth noting that the localization of this function, also achieved by searching for hardcoded patterns, is very exhaustive and even contains patterns corresponding to the Redstone 1 release from August 2016.

  7. The Windows kernel then starts, and ends up calling the hooked ZwCreateSection function while running normally. When that happens, CosmicStrand gains control of the execution again, and restores the original code before running more malicious code.
  8. The ZwCreateSection hook’s primary purpose is to collect the addresses of API functions provided by the kernel, and create a sort of import table for the next component. Using the resolved functions, it also allocates a buffer in the kernel’s address space where it maps a shellcode, before calling it.
Kernel shellcode

All the steps described so far only served the purpose of propagating code execution from the UEFI down to the Windows kernel. This shellcode is the first actually malicious component of the chain so far. It sets up a thread notify routine that gets invoked each time a new thread is created. CosmicStrand waits until one turns up in winlogon.exe, and then executes a callback in this high-privilege context.

There, CosmicStrand sleeps for 10 minutes and tests the internet connectivity of the infected machine. CosmicStrand doesn’t rely on high-level API functions to generate network traffic, but instead interacts directly with the Transport Device Interface: it generates the needed IRPs (I/O request packets) and passes them to the network stack by sending IOCTLs to the TCP or UDP device object. DNS requests are performed in this fashion, using either Google’s DNS server (8.8.8[.]8) or a custom one (222.222.67[.]208).

CosmicStrand retrieves its final payload by sending a specifically crafted UDP (preferably) or TCP packet to its C2 server, update.bokts[.]com. The reply is expected to return in one or several packets containing chunks of 528 bytes following this structure:

Offset (bytes) Description 0-4 Magic number 4-8 Total length of the payload 8-12 Length of the current chunk 12-16 CRC32 checksum of the current chunk 16-* Payload chunk

The various chunks are reassembled into a series of bytes that are mapped into kernel space and interpreted as a shellcode. Unfortunately, we were not able to obtain a copy of data coming from the C2 server. We did, however, find a user-mode sample in-memory on one of the infected machines we could study, and believe it is linked with CosmicStrand. This sample is an executable that runs command lines in order to create a user (“aaaabbbb”) on the victim’s machine and add it to the local administrators group.

We can infer from this that shellcodes received from the C2 server might be stagers for attacker-supplied PE executables, and it is very likely that many more exist.

Older CosmicStrand variants

During the course of our investigation, we also discovered older versions of this rootkit. They feature the same deployment process and their minute differences pertain to the kernel shellcode.

  • It attempts to hijack a thread from exe instead of winlogon.exe.
  • The C2 domain contacted to obtain additional shellcode in order to run is different (erda158[.]to).
  • The older variant printed debugging messages every time a new process was created in the system.

Based on our analysis of the infrastructure used for the two variants, we estimate that the older one saw use between the end of 2016 and mid-2017, and the current one was active in 2020.


We are aware of two C2 servers, one for each variant. According to passive DNS data available for them, these domains had a long lifetime and resolved to IP addresses during limited timeframes – outside of which the rootkit would have been inoperative. It is therefore interesting to note that while the attackers opted to deploy an extremely persistent implant, the actual exploitation of the victim machines may not have lasted more than a few months. It is, however, possible that these domains were occasionally reactivated for very short durations, and that this information would not have been recorded by passive DNS systems.

Domain IP First seen Last seen ASN www.erda158[.]top 58.84.53[.]194 2016-12-27 2017-04-26 AS48024 (NEROCLOUD) 115.239.210[.]27 2017-04-30 2017-06-24 AS58461 (CHINANET) update.bokts[.]com 23.82.12[.]30 2020-05-03 2020-05-03 AS30633 (Leaseweb USA) 23.82.12[.]31 2020-07-25 2020-07-25 AS30633 (Leaseweb USA) 23.82.12[.]32 2020-03-09 2020-07-25 AS30633 (Leaseweb USA)

Careful readers will notice the three-year gap between the activity periods of the two domains. It is possible that during that time, the attackers were controlling the victim’s machines using user-mode components deployed through CosmicStrand, or (more likely) that other variants and C2 servers that we did not yet discover exist somewhere.


We were able to identify victims of CosmicStrand in China, Vietnam, Iran and Russia. A point of interest is that all the victims in our user base appear to be private individuals (i.e., using the free version of our product) and we were unable to tie them to any organization or even industry vertical.


Several data points lead us to believe that CosmicStrand was developed by a Chinese-speaking threat actor, or by leveraging common resources shared among Chinese-speaking threat actors. Specifically, a number of code patterns featured in CosmicStrand were also observed in another malware family, the MyKings botnet (e.g., MD5 E31C43DD8CB17E9D68C65E645FB3F6E8). This botnet, used to deploy cryptominers, was documented by Sophos in 2020 where they noted the presence of several Chinese-language artifacts.

Similarities with CosmicStrand include:

  • The use of an MBR rootkit to establish stealthy persistence in MyKings.
  • CosmicStrand and MyKings use identical tags when they allocate memory in kernel mode (Proc and GetM).
  • Both families generate network packets the same way, and leverage the UDP and TCP device objects directly.
  • The API hashing code used in the two of them is identical, as evidenced by the screenshot below. As far as we know, this algorithm was only ever found in two other rootkits, MoonBounce and xTalker – also tied to Chinese-speaking threat actors.

In addition to this code similarity, the fact that the hardcoded fallback DNS server used by CosmicStrand is located in CHINANET-BACKBONE (AS4134) could be perceived as a very low-confidence sign that the attackers are part of the Chinese-speaking nexus. Beyond this tie, we have decided that we do not have sufficient information that would allow us to link CosmicStrand to an existing cluster.


CosmicStrand is a sophisticated UEFI firmware rootkit that allows its owners to achieve very durable persistence: the whole lifetime of the computer, while at the same time being extremely stealthy. It appears to have been used in operation for several years, and yet many mysteries remain. How many more implants and C2 servers could still be eluding us? What last-stage payloads are being delivered to the victims? But also, is it really possible that CosmicStrand has reached some of its victims through package “interdiction”? In any case, the multiple rootkits discovered so far evidence a blind spot in our industry that needs to be addressed sooner rather than later.

The most striking aspect of this report is that this UEFI implant seems to have been used in the wild since the end of 2016 – long before UEFI attacks started being publicly described. This discovery begs a final question: if this is what the attackers were using back then, what are they using today?

The GReAT team would like to extend its special thanks to their former colleague, Mark Lechtik, for his key involvement in this research.


[1] A hook is a modification to the normal flow of execution of a program. It aims to execute additional code provided by the attacker before or after a given function. In some environments, function hooking is provided for legitimate purposes and can be set up easily through conventional programming mechanisms. In other cases, where they are not explicitly supported, attackers can still achieve hooking by overwriting (and later on, restoring) the code that is about to be executed. Both cases are leveraged by this rootkit.

[2] Here we skip the implementation details and shellcode tricks used by the rootkit in order to obtain the address of the malicious code. The precise workflow of this part is left as an exercise to the reader, and documented extensively in our private report on this activity.

[3] More information about this function is available in research from other vendors.

Magecart Hacks Food Ordering Systems to Steal Payment Data from Over 300 Restaurants

The Hacker News - 25 Červenec, 2022 - 11:07
Three restaurant ordering platforms MenuDrive, Harbortouch, and InTouchPOS were the target of two Magecart skimming campaigns that resulted in the compromise of at least 311 restaurants. The trio of breaches has led to the theft of more than 50,000 payment card records from these infected restaurants and posted for sale on the dark web. "The online ordering platforms MenuDrive and Harbortouch Ravie Lakshmanan
Kategorie: Hacking & Security

Racoon Stealer is Back — How to Protect Your Organization

The Hacker News - 25 Červenec, 2022 - 10:52
The Racoon Stealer malware as a service platform gained notoriety several years ago for its ability to extract data that is stored within a Web browser. This data initially included passwords and cookies, which sometimes allow a recognized device to be authenticated without a password being entered. Racoon Stealer was also designed to steal auto-fill data, which can include a vast trove of The Hacker News
Kategorie: Hacking & Security

Roaming Mantis Financial Hackers Targeting Android and iPhone Users in France

The Hacker News - 25 Červenec, 2022 - 06:49
The mobile threat campaign tracked as Roaming Mantis has been linked to a new wave of compromises directed against French mobile phone users, months after it expanded its targeting to include European countries. No fewer than 70,000 Android devices are said to have been infected as part of the active malware operation, Sekoia said in a report published last week. Attack chains involving Roaming Ravie Lakshmanan
Kategorie: Hacking & Security

Linux x86 32-bit Is Vulnerable To Retbleed But Don't Expect It To Get Fixed - 24 Červenec, 2022 - 14:03
While relevant Intel and AMD processors have been mitigated for the recent Retbleed security vulnerability affecting older generations of processors, those mitigations currently just work for x86_64 kernels and will not work if running an x86 (32-bit) kernel on affected hardware. But it's unlikely to get fixed unless some passionate individual steps up as the upstream developers and vendors have long since moved on to just caring about x86_64.
Kategorie: Hacking & Security

What Is Oracle Linux? The Powerful, Free RHEL Alternative Explained - 24 Červenec, 2022 - 14:01
Oracle Linux is an enterprise-grade Linux distro with no licensing fee, unlike RHEL. Here's everything you need to know about it.
Kategorie: Hacking & Security

Office macro security: on-again-off-again feature now BACK ON AGAIN!

Sophos Naked Security - 23 Červenec, 2022 - 20:10
20 years to turn it on, then 20 weeks to turn it off, then just 2 weeks to turn it back on again. That's progress!

SonicWall Issues Patch for Critical Bug Affecting its Analytics and GMS Products

The Hacker News - 22 Červenec, 2022 - 20:35
Network security company SonicWall on Friday rolled out fixes to mitigate a critical SQL injection (SQLi) vulnerability affecting its Analytics On-Prem and Global Management System (GMS) products. The vulnerability, tracked as CVE-2022-22280, is rated 9.4 for severity on the CVSS scoring system and stems from what the company describes is an "improper neutralization of special elements" used in Ravie Lakshmanan
Kategorie: Hacking & Security

Facebook vás tajně neodposlouchává. Má mnohem lepší způsoby, než vás sledovat přes mikrofon - bezpečnost - 22 Červenec, 2022 - 18:45
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Kategorie: Hacking & Security

Zabijácký robopes se střílnou na hřbetě je realitou. V Rusku ho vytvořili z čínského klonu Spota - bezpečnost - 22 Červenec, 2022 - 17:45
Robopsa Spota od Boston Dynamics zná díky celé řadě vtipných videí určitě každý a nějakou dobu se dá už koupit pro reálné použití v průmyslu nebo pro další výzkum. Cena robopsa Spot v plné výbavě je ale klidně několik milionů korun, což značně omezuje poptávku a možnosti. Na čínském Aliexpressu lze ...
Kategorie: Hacking & Security

Hackeři změnili s příchodem léta taktiku. Útoky jsou přesně cílené - bezpečnost - 22 Červenec, 2022 - 14:17
Odesílání co největšího množství podvodných e-mailů se ukázalo evidentně jako neefektivní. S příchodem léta tak hackeři změnili taktiku, své útoky na uživatele v Česku přesně cílí. Vyplývá to z analýzy antivirové společnosti Eset.
Kategorie: Hacking & Security

Microsoft Resumes Blocking Office VBA Macros by Default After 'Temporary Pause'

The Hacker News - 22 Červenec, 2022 - 14:17
Microsoft has officially resumed blocking Visual Basic for Applications (VBA) macros by default across Office apps, weeks after temporarily announcing plans to roll back the change. "Based on our review of customer feedback, we've made updates to both our end user and our IT admin documentation to make clearer what options you have for different scenarios," the company said in an update on July Ravie Lakshmanan
Kategorie: Hacking & Security

Windows, Linux, ESXi Systems Targeted by Novel Luna Ransomware - 22 Červenec, 2022 - 13:44
Windows, Linux, and ESXi systems could be encrypted with the novel Luna ransomware family, which is believed to be developed by Russian-speaking threat actors, according to BleepingComputer .
Kategorie: Hacking & Security

Google Bringing the Android App Permissions Section Back to the Play Store

The Hacker News - 22 Červenec, 2022 - 11:19
Google on Thursday said it's backtracking on a recent change that removed the app permissions list from the Google Play Store for Android across both the mobile app and the web. "Privacy and transparency are core values in the Android community," the Android Developers team said in a series of tweets. "We heard your feedback that you find the app permissions section in Google Play useful, and Ravie Lakshmanan
Kategorie: Hacking & Security

An Easier Way to Keep Old Python Code Healthy and Secure

The Hacker News - 22 Červenec, 2022 - 11:00
Python has its pros and cons, but it's nonetheless used extensively. For example, Python is frequently used in data crunching tasks even when there are more appropriate languages to choose from. Why? Well, Python is relatively easy to learn. Someone with a science background can pick up Python much more quickly than, say, C. However, Python's inherent approachability also creates a couple of The Hacker News
Kategorie: Hacking & Security
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