Babuk: Did they bite off more than they could chew when they aimed to Encrypt VM and *nix Systems?

By Thibault Seret, Security Researcher, McAfee

For a long time, ransomware gangs were mostly focused on Microsoft Windows operating systems. Yes, we observed the occasional dedicated Unix or Linux based ransomware, but cross-platform ransomware was not happening yet. However, cybercriminals never sleep and in recent months we noticed that several ransomware gangs were experimenting with writing their binaries in the cross-platform language Golang (Go).

Our worst fears were confirmed when Babuk announced on an underground forum that it was developing a cross-platform binary aimed at Linux/UNIX and ESXi or VMware systems. Many core backend systems in companies are running on these *nix operating systems or, in the case of virtualisation, think about the ESXi hosting several servers or the virtual desktop environment.

We touched upon this briefly in our previous blog, together with the many coding mistakes the Babuk team is making.

Even though Babuk is relatively new to the scene, its affiliates have been aggressively infecting high-profile victims, despite numerous problems with the binary which led to a situation in which files could not be retrieved, even if payment was made.

Ultimately, the difficulties faced by the Babuk developers in creating ESXi ransomware may have led to a change in business model, from encryption to data theft and extortion.

Indeed, the design and coding of the decryption tool are poorly developed, meaning if companies decide to pay the ransom, the decoding process for encrypted files can be really slow and there is no guarantee that all files will be recoverable.

McAfee’s EPP solution covers Babuk ransomware with an array of prevention and detection techniques.

McAfee ENS ATP provides behavioral content focusing on proactively detecting the threat while also delivering known IoCs for both online and offline detections. For DAT based detections, the family will be reported as Ransom-Babuk!. ENS ATP adds two additional layers of protection thanks to JTI rules that provide attack surface reduction for generic ransomware behaviors and RealProtect (static and dynamic) with ML models targeting ransomware threats.

Updates on indicators are pushed through GTI, and customers of Insights will find a threat-profile on this ransomware family that is updated when new and relevant information becomes available.

Initially, in our research the entry vector and the complete tactics, techniques and procedures (TTPs) used by the criminals behind Babuk remained unclear.

However, when its affiliate recruitment advertisement came online, and given the specific underground meeting place where Babuk posts, defenders can expect similar TTPs with Babuk as with other Ransomware-as-a-Service families.