The threat actor known as
ChamelGang has been observed using a previously undocumented implant to backdoor Linux systems, marking a new expansion of the threat actor's capabilities.
The malware, dubbed
ChamelDoH by Stairwell, is a C++-based tool for communicating via DNS-over-HTTPS (
DoH) tunneling.
The Linux backdoor discovered by Stairwell, for its part, is designed to capture system information and is capable of remote access operations such as file upload, download, deletion, and shell command execution.
What makes ChamelDoH unique is its novel communication method of using DoH, which is used to perform Domain Name System (DNS) resolution via the HTTPS protocol, to send DNS TXT requests to a rogue nameserver.
"Due to these DoH providers being commonly utilized DNS servers [i.e., Cloudflare and Google] for legitimate traffic, they cannot easily be blocked enterprise-wide," Stairwell researcher Daniel Mayer said.
