If you thought Cisco routers were immune to attacks, think again. Security researcher Sebastian Muniz plans to unveil a malicious rootkit software he devloped for Cisco's routers. Computerworld reports that he will demonstrate the rootkit May 22 at the EuSecWest conference in London.

The rootkit won't allow an attacker to break into a router, but it will silently monitor and control the device. This is the first time someone has written a rootkit specifically for the Internetworking Operating System used by Cisco's routers. In the past, malicious software was aimed at a particular version of IOS, but Muniz says his rootkit can work on several different versions.

Muniz, who works at Core Security Technologies Inc., says he doesn't plan to release the source code for his rootkit. He claims his point in creating it is to show that Cisco routers aren't immune to malware and security measures must be taken.

What makes this rootkit particularly worrisome is the fact that routers from Cisco are widely used. Moreover, a recently leaked FBI report shows that tampering at the supply-chain level is not out of the question.

Earlier this year, IT BusinessEdge blogger Carl Weinschenk reported that rootkits were on the rise. It would be in the best interest of IT managers and security forces to pay attention.