A security researcher has developed malicious rootkit software for all Cisco routers.
Sebastian Muniz, a researcher with penetration testing firm Core Security Technologies, has developed the software, and will demonstrate it at next week's EuSecWest security conference in London.
Rootkits are malware that can hide themselves in systems while they allow remote hackers to use them to gain access.
Muniz has developed rootkit software that targets IOS, the operating system used by all Cisco routers to power enterprise networks and the web.
As Cisco controls the lion's share of the router market, his demonstration on 22 May may well kick-start a trend among other hackers to use rootkits to target web and enterprise networks.
In the past, hackers have been able to write "shell code" aimed at compromising a single version of IOS. Muniz' effort, however, can be used against all versions of IOS.
His code can not be used to break into a router, however. Any attacker could only install it if they gained access privileges or came up with their own separate attack code.