The FBI (Federal Bureau of Investigation) will arrest a teenager it believes wrote one of the variants of the W32.Blaster worm today.

The unnamed 18-year old, believed by the FBI and the Department of Justice (DOJ) to be the author of the Blaster-B variant, is expected to be arrested in Seattle today, according to The Wall Street Journal.

The worm launched denial of service attacks against Microsoft's Web site as well as opening a back door into infected machines.

The virus affected Windows 2000, Windows XP, Windows NT and Windows Server 2003. Windows 95, 98 and Millennium Edition. It did not affect Mac or Linux systems.

A news conference by the Seattle offices of the DOJ and FBI is scheduled for 1.30pm (9.30pm GMT) today.