Summary

This boot sector virus is known to be in the wild in the Netherlands.

WET is only able to infect a hard disk when you try to boot the machine from an infected diskette. At this time WET infects the DOS boot sector on hard drive, and after that it will go resident to high DOS memory during every boot-up from the hard disk. When WET infects floppies, it does not save the original boot sector anywhere.

Additional Details

Most other boot sector viruses infect the MBR on hard drives, not the DOS boot sector.

Once WET gets resident to memory, it will infect practicly all non-writeprotected diskettes used in the machine. WET uses stealth mechanisms to conceal it's presence.

The following text string can be seen in infected boot sectors:

            (c) 1990 W.E.T.

The virus is suspected to have been written signifantly later than the copyright statement implies.

WET also ovewrites the file system type in the boot sector with its own code. The side effect from this is that the DOS sys command can NOT be used to overwrite the boot sector on the hard drive - it will just produce an error.

WET is difficult to remove unless you have a program capable of disinfecting it. Contact F-Secure anti-virus support for more info.

[Analysis: Mikko Hypponen, F-Secure]