For the first time, security researchers have uncovered and analyzed a Linux variant of Winnti, one of the favorite hacking tools used by Beijing hackers over the past decade.
Discovered by security researchers from Chronicle, Alphabet’s cyber-security division, the Linux version of the Winnti malware works as a backdoor on infected hosts, granting attackers access to compromised systems.
Chronicle says it discovered this Linux variant after news broke last month that Bayer, one of the world’s largest pharmaceutical companies, had been hit by Chinese hackers, and the Winnti malware was discovered on its systems.
During subsequent scans for Winnti malware on its VirusTotal platform, Chronicle said it spotted what appeared to be a Linux variant of Winnti, dating back to 2015 when it was used in the hack of a Vietnamese gaming company.
Chronicle says the malware they discovered was made up of two parts. A rootkit component to hide the malware on infected hosts, and the actual backdoor trojan.
Further analysis revealed code similarities between the Linux version and the Winnti 2.0 Windows version, as described in reports by Kaspersky Lab and Novetta.
Other connections with the Windows version also included the similar way in which the Linux variant handled outbound communications with its command-and-control (C&C) server — which was a mixture of multiple protocols (ICMP, HTTP, and custom TCP and UDP protocols).
Last but not least, the Linux version also possessed another feature that was distinctive to the Windows version, which was the ability for Chinese hackers to initiate connections to infected hosts without going through the C&C servers.
Submitted by: Arnfried Walbrecht