Yet another Linux malware spotted in the wild

February 26, 2016

The Dell Sonicwall Threat Research team has received reports of yet another Trojan targeting the Linux platform. Linux is widely used across many enterprise environments nowadays which make them lucrative targets by devious cybercriminals. This Trojan was reported to be created by the Sednit espionage group who are known to target organizations such as the government and military. The Trojan is capable of remotely executing arbitrary commands and keylogging.

Infection Cycle:

It copies itself as "ksysdefd" in the following locations:

  • ~/.config/ksysdef/ksysdefd
  • /bin/ksysdefd

In order to ensure that it autoruns, it adds the strings "./bin/ksysdefd & exit 0" to the rc.local file in the /etc/ directory:

It also creates the directory ~/.local/cva-ssys and saves its additional components within it.

It checks for which distribution of Linux it runs on.

And also checks for the type of desktop environment.

Looking further in its strings reveals additional capabilities of this Trojan like the ability of executing commands remotely, deleting and writing files and keylogging, among others.
Sednit capabilities found in strings

While the Trojan did not make any active network connections at the time of analysis, it has demonstrated to employ an effective way to stay undetected especially for inexperienced users as it gathers data from a victim's machine.

Dell SonicWALL Gateway AntiVirus provides protection against this threat with the following signature:

  • GAV: Linux.Sednit.EL (Trojan)