A new sophisticated, unique Linux malware dubbed HiddenWasp used in targeted attacks against victim’s who are already under attack or gone through a heavy reconnaissance.
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.”
According to the report, both the rootkits and the trojan help each other to maintain the persistence in the system “having the rootkit attempting to hide the trojan and the trojan enforcing the rootkit to remain operational.”
Researchers linked the malware with Chinese open-source rootkit for Linux known as Adore-ng, and this malware is aiming to intrude already compromised servers and the communication between the trojan and C&C server established over SNMP protocol.
Here is the list of trojan’s functionalities based on the requests. Enterprises can prevent Intrusion by blocking Command-and-Control IP addresses.