Threat Signal Report
Cobalt Strike Delivered Through Fake Proof-of-Concept Code
FortiGuard Labs is aware of a report that a Cobalt Strike beacon was attempted to be delivered through a couple of fake Proof-of-Concept (POC) codes hosted on GitHub. The files pretend to be POCs for CVE-2022-26809 and CVE-2022-24500. They have already been removed from GitHub.
Why is this Significant?
This is significant because the attack targeted researchers, pen testers and infosec teams in organizations to deliver Cobalt Strike beacons, which will most likely be used to deliver malware such as ransomware.
What is CVE-2022-26809?
CVE-2022-26809 is a remote procedure call runtime remote code execution vulnerability that affects wide variety of Windows OS that includes Windows 7, 8, 10, 11, Windows Server 2008, 2012, 2016, 2019 and 2022. Assigned a CVSS score of 9.8, successfully exploiting the vulnerability allows an attacker to execute remote code with high privileges on a vulnerable system, leading to a full compromise. The vulnerability was patched as part of Patch Tuesday April 2022.
FortiGuard Labs previously released Threat Signal on CVE-2022-26809. See the Appendix for a link to "Microsoft Released Advisory on a Critical Remote Code Execution Vulnerability in RPC (CVE-2022-26809)".
What is CVE-2022-24500?
CVE-2022-24500 is a Windows SMB remote code execution vulnerability that affects Windows 7, 8, 10, 11 and Windows Server 2008, 2012, 2019 and 2022. The vulnerability has a CVSS score of 8.8, and was patched as part of Patch Tuesday April 2022.
The Microsoft advisory states that "For vulnerability to be exploited, a user would need to access a malicious SMB server to retrieve some data as part of an OS API call. This vulnerability requires that a user with an affected version of Windows access a malicious server. An attacker would have to host a specially crafted server share or website. An attacker would have no way to force users to visit this specially crafted server share or website, but would have to convince them to visit the server share or website, typically by way of an enticement in an email or chat message".
What is Status of Coverage?
FortiGuard Labs detect the fake POCs with the following AV coverage:
All network IOC's are blocked by the WebFiltering client.
Traffic Light Protocol
|Color||When Should it Be used?||How may it be shared?|
TLP: REDNot for disclosure, restricted to participants only.
|Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused.||Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.|
TLP: AMBERLimited disclosure, restricted to participants’ organizations.
|Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved.||Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.|
TLP: GREENLimited disclosure, restricted to the community.
|Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector.||Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.|
TLP: WHITEDisclosure is not limited.
|Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release.||Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.|