ACHTUNG! Scary Linux system backdoor turns boxes into DDoS droids
Xnote.1 - the Swiss Army knife of malware
Cybercrooks have cooked up a backdoor for Linux-powered systems that boasts multiple malicious functions.
The Swiss Army Knife-style malware – dubbed Xnote.1 by Russian anti-virus company Doctor Web – can be used as a platform to mount distributed denial-of-service attacks and other evil activities.
To spread the software nasty, "criminals mount a brute force attack to establish an SSL connection with a target machine," say researchers. It's not entirely clear what this means: a particular attack against a HTTPS server, or a typo – and that it's actually a password brute-force assault against a SSH server.
We reckon it's a typo – the original Russian writeup on the malware mentions SSH.
The malware will only be installed in a system if the crims have been able to get superuser (root) privileges. Routines in the malicious code prevent its re-installation on compromised machines. Once installed, Xnote.1 phones home with information about the infiltrated systems to a control server.
The malware then opens a backdoor, allowing it to receive and execute commands from crooks. You can defend against this nasty by installing fail2ban, using strong shell account passwords, or using SSH keys.
Security researchers at Doctor Web reckon a Chinese hacking crew is behind the spread of the malware. A full write-up of the malware can be found in a blog post by Doctor Web here. ®