A Department of Homeland Security (DHS) official responsible for defending US government networks against cyberattacks resigned on Monday.

Randy Vickers stepped down as director of the US Computer Emergency Readiness Team (US-CERT), the operational arm of the DHS's National Cyber Security Division.

Information Week, which first reported Vickers' resignation, noted that it followed a string of cyberattacks on US government networks by hacker groups such as Anonymous and Lulz Security.

An AFP article that Vickers' resignation was effective on Friday. She said he would be replaced by US-CERT deputy director Lee Rock until a new director is named.