Unboxing Linux/Mumblehard: Muttering spam from your servers (WeLiveSecurity)

By ris WeLiveSecurity reports
that ESET researchers have revealed a family of Linux malware that stayed
under the radar for more than 5 years. They are calling it
Linux/Mumblehard. “There are two components in the Mumblehard malware family: a backdoor and a spamming daemon. They are both written in Perl and feature the same custom packer written in assembly language. The use of assembly language to produce ELF binaries so as to obfuscate the Perl source code shows a level of sophistication higher than average.

Monitoring of the botnet suggests that the main purpose of Mumblehard seems to be to send spam messages by sheltering behind the reputation of the legitimate IP addresses of the infected machines.”

From: LWN