W32.Alcra. F is a computer worm that is spread by P2P file sharing networks. It is regarded as a low-risk virus,[1] and is usually detected by a virus scan.
The W32.Alcra. F worm saves a number of empty files and links to a computer, and then attempts to connect to those links thus causing an error.
A full system scan usually can find, and remove this worm without much difficulty.