Undetected malware attacks Linux systems
The malware is highly sophisticated and went undetected; the malware is still active and has a zero detection rate. The malware adopted a massive amount of codes from publically available malware such as Mirai and the Azazel rootkit.
Unlike Windows malware, Linux malware authors won’t concentrate much with evasion techniques, as the trend of using Anti-Virus solutions in Linux machine is very less when compared to other platforms.
However, the Intezer report shows “malware with strong evasion techniques does exist for the Linux platform. There is also a high ratio of publicly available open-source malware that utilizes strong evasion techniques and can be easily adapted by attackers.”
In the past, we saw many malware focussed on crypto-mining or DDoS activity, but the HiddenWasp is purely a targeted remote control attack.
The malware is composed of a user-mode rootkit, a trojan, and an initial deployment script. Researchers spotted the files went undetected in VirusTotal and the malware hosted in servers of a hosting company ThinkDream located in Hong Kong.
While analyzing scripts, Intezer spotted a user named ‘sftp’ and hardcodes, which can be used for initial compromise and also the scripts has variable to clear the older versions from the compromised systems.
The scripts also include variables to determine server architecture of the compromised system and download components from the malicious server based on the compromised server architecture. Once the components installed, the trojan will get executed on the system.
“Within this script, we were able to observe that the main implants were downloaded in the form of tarballs. As previously mentioned, each tarball contains the main trojan, the rootkit, and a deployment script for x86 and x86_64 builds accordingly.”