W32.Lorsis.Worm is a worm that spreads through the KaZaA file-sharing network. If this worm is executed in February, or from December 6 to 31, it deletes critical system files.
The worm uses several different filenames ending with " .exe" (there are 15 spaces before the .exe extension); see the "Technical Details" section for a complete list.
During execution, the worm repeatedly attempts to copy itself to the A: drive, resulting in noticeable noise from the floppy drive, if one is installed.
W32.Lorsis.Worm is written in Visual Basic and is compressed with Aspack and UPX.
Infection Length: 78848
Systems Affected: Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP, Windows Me
Systems Not Affected: Windows 3.x, Macintosh, OS/2, UNIX, Linux