The Winnti criminal organization is known for industrial cyber-espionage campaigns targeting software companies, especially those in the gaming industry. Recently it moved to the lucrative telecoms and big pharma businesses.
Kaspersky Lab has called the threat “HDRoot” after the original tool’s name “HDD Rootkit”. It is based on a 2006 bootkit installer, and is a universal platform for a sustainable and persistent appearance in a targeted system, which can be used as a foothold for any arbitrary tool.
“HDRoot” was discovered when a sample of malware sparked the interest of Kaspersky Lab’s Global Research and Analysis Team (GReAT) for the following reasons:
- It was protected with a commercial VMProtect Win64 executable signed with a known compromised certificate belonging to the Chinese entity, Guangzhou YuanLuo Technology. The Winnti group is known to have abused this certificate in the past to sign other tools
- The properties and output text of the executable were spoofed to make it look like a Microsoft’s Net Command net.exe, to reduce the risk of system administrators exposing the program as hostile
GReAT researchers were able to identify two types of backdoors launched with the help of this platform, but there may be more. One of these backdoors was able to bypass well-established anti-virus products in South Korea - AhnLab’s V3 Lite, AhnLab’s V3 365 Clinic and ESTsoft’s ALYac, where Winnti used it to launch malware products on its targets.
Andrew Mamonitis, Managing Director at Kaspersky Lab ANZ says, “The most important goal for any APT-actor is to stay under the radar. That is why we rarely see any complicated code encryption. The Winnti group took a risk, because it probably knows from experience which signs should be covered-up and which can be overlooked, as organizations don’t always apply all the best security policies all of the time. System administrators have to keep on top of many things, and if the team is small, the chance that cyber-criminal activity will remain undetected is even higher”.
This is an active threat. Since Kaspersky Lab started to add detections, the group behind the attacks has started to adapt them. In less than one month, a new modification was identified.
Kaspersky Lab’s products successfully block the malware and protect users against the threat.