A piece of malware designed to launch brute-force password guessing attacks against websites built with popular content management systems like WordPress and Joomla has started being used to also attack email and FTP servers.
The malware is known as Fort Disco and was documented in August by researchers from DDoS mitigation vendor Arbor Networks who estimated that it had infected over 25,000 Windows computers and had been used to guess administrator account passwords on over 6,000 WordPress, Joomla and Datalife Engine websites.
Once it infects a computer, the malware periodically connects to a command and control (C&C) server to retrieve instructions, which usually include a list of thousands of websites to target and a password that should be tried to access their administrator accounts.
The Fort Disco malware seems to be evolving, according to a Swiss security researcher who maintains the Abuse.ch botnet tracking service. "Going down the rabbit hole, I found a sample of this particular malware that was brute-forcing POP3 instead of WordPress credentials," he said Monday in a blog post.