Symantec has announced the discovery of a new worm that attacks Linux systems. The potential targets include Linux computers, as well as home routers, set-top boxes, and other devices running embedded Linux. The Linux.Darlloz worm spreads by exploiting a vulnerability in php-cgi. Security experts have been aware of this exploit for over a year, and patches have been available for Linux systems since May 2012; however, unpatched home computers and embedded devices that rarely see updates are potentially vulnerable to attack.
According to Symantec's Kaoru Hayashi, who announced the worm on his blog, “...the worm generates IP addresses randomly, accesses a specific path on the machine with well known ID and passwords, and sends HTTP POST requests, which exploit the vulnerability. If the target is unpatched, it downloads the worm from a malicious server and starts searching for its next target.”
Hayashi states that the ultimate target for this attack could be the “Internet of Things.” Although the variant discovered in the lab is designed for attacking x86 systems, it appears the attacker has other versions of the worm tailored for ARM, PPC, MIPS, and MIPSEL architectures.
To keep the worm away, Symantec recommends the usual precautions, such as installing the latest software versions and patches and using stronger passwords. Also, Hayashi's blog post recommends configuring the gateway to block incoming HTTP POST requests to -/cgi-bin/php and several other specific paths related to php-cgi.