Volt Typhoon, also known as the Bronze Silhouette, has been discovered to be linked with a complex botnet called “KV-botnet.”
The threat actor has been using this botnet to target Small Office/Home Office routers since at least February 2022. Their primary targets are routers, firewalls, and VPN devices which are utilized for proxying malicious traffic.
According to reports from Microsoft and the US government, this threat actor is building their infrastructure to disrupt communications between the USA and Asia in case of future conflicts.
Chinese Hackers Seized Outdated Routers
The IP addresses used for the campaign were attributed to the People’s Republic of China, according to the report shared with Cyber Security News.
In addition to this, the operations took place during the working hours of Chinese Standard Time, which adds additional confidence about the threat actor’s origin.
The botnet is divided into two distinct activities: the “JDY cluster,” which has less sophisticated techniques for scanning targets, and the “KV cluster,” which is reserved for manual operations against high-profile targets.
Moreover, the botnet also targets end-of-life devices that are being used by SOHO entities as they have low security and are easy to exploit. The devices focussed specifically were Cisco RV320s, DrayTek Vigor routers, and NETGEAR ProSAFE firewalls.
Infection Chain
The threat actor uses multiple files, including a bash script file, for their infection chain. They half-specific processes and remove security tools that defaultly run on the compromised devices.
As part of the evasion techniques, the botnets are set up with random ports for C2 communication and also disguise their names as existing processes.
Threat actors communicate with these botnets and perform data exfiltration, data transmission, creation of network connections, task execution, and many others.
Furthermore, a complete report about this botnet has been published, which provides detailed information about the botnet infection chain, process execution, attack methods, evasion techniques, and other information.