A pair of recently disclosed zero-day flaws in Ivanti Connect Secure (ICS) virtual private network (VPN) devices have been exploited to deliver a Rust-based payload called KrustyLoader that’s used to drop the open-source Sliver adversary simulation tool.
The security vulnerabilities, tracked as CVE-2023-46805 (CVSS score: 8.2) and CVE-2024-21887 (CVSS score: 9.1), could be abused in tandem to achieve unauthenticated remote code execution on susceptible appliances.
Following public disclosure earlier this month, the vulnerabilities have come under broad exploitation by other adversaries to drop XMRig cryptocurrency miners as well as Rust-based malware.
Synacktiv’s analysis of the Rust malware, codenamed KrustyLoader, has revealed that it functions as a loader to download Sliver from a remote server and execute it on the compromised host.
Sliver, developed by cybersecurity company BishopFox, is a Golang-based cross-platform post-exploitation framework that has emerged as a lucrative option for threat actors in comparison to other well-known alternatives like Cobalt Strike.
“Both Havoc and Mythic have also become relatively popular but are still observed in far lower numbers than Cobalt Strike, Meterpreter, or Viper,” the company said. “Four other well-known frameworks are Sliver, Havoc, Brute Ratel (BRc4), and Mythic.”
Source: https://thehackernews.com/