Illuminating The Etumbot APT Backdoor
The Arbor Security Engineering Response Team (ASERT) has released a research paper concerning the Etumbot malware.
Etumbot is a backdoor used in targeted attacks since at least March 2011. Indicators suggest that Etumbot is associated with the Numbered Panda group, also known as IXEHSE, DynCalc, and APT12. Although previous research has covered related malware, little has been publicly discussed regarding Etumbot’s capabilities.
Indicators suggest that the Etumbot dropper is delivered via spear phishing and is contained inside an archive file intended to be of interest to the target. The attackers use the Unicode Right to Left Override technique and document icons to disguise malicious executable content as document files. Once the dropper is executed, the backdoor is activated and a distraction file of interest to the target is opened for viewing. ASERT has observed several Etumbot samples using distraction documents involving Taiwanese and Japanese topics of interest, and has also observed recent development activity which indicates that attack campaigns are ongoing.
Once installed, the backdoor connects to it’s Command & Control server and receives an encryption key. RC4 encryption, along with HTTP transactions intended to blend in with typical traffic are used for backdoor communications. Etumbot’s core functionality Continue reading
