What is "swen"

Swen is a mass mailing computer worm written in C++. It sends an email which contains the installer for the virus, disguised as a Microsoft Windows update, although it also works on P2P filesharing networks, IRC and newsgroups' websites. It was first analyzed on September 18, 2003, however, it might have infected computers before then. It disables firewalls and antivirus programs.