Threat Actor Abuses Microsoft’s WHCP to Sign Malicious Drivers
Microsoft is investigating an incident where a threat actor submitted malicious drivers for certification through the Windows Hardware Compatibility Program.
Built by a third-party, the drivers were designed to target gaming environments and could allow the attacker to spoof their location and play from anywhere.
Immediately upon learning of the issue, Microsoft said it suspended the offending account and started reviewing their submissions to identify any additional malware.
The company also added detection rules in Microsoft Defender for Endpoint to block the driver and its associated files, and also shared the information with other security vendors.
“We have seen no evidence that the WHCP signing certificate was exposed. The infrastructure was not compromised,” Microsoft says.
Microsoft believes the the threat actor is specifically targeting the gaming sector in China, and that it has no interest in hitting enterprise environments.
Microsoft also notes that the malicious driver appears meant to help the adversary spoof geo-location data to be able to cheat and play games from anywhere. This may also allow the threat actor to possibly compromise other players’ accounts through keyloggers and other common tools.
“We are not attributing this to a nation-state actor at this time,” Microsoft says.
The tech giant also explains that the identified driver is used post exploitation, with the attacker first gaining administrative privileges to install the malicious driver, or convincing the targeted user to do it.
Security researchers at antivirus company G Data were the first to discover the malicious driver. Named Netfilter, the threat acts like a rootkit and was designed for IP redirection, the researchers say.
The threat fetches the IP addresses and the redirection target from a specific address that is also used for the malware’s self-update routine, as well as to receive a root certificate that is added to registry.