W32/Crasher is a virus that infects all the files in the system.

Upon execution, it attempts to modify all the files(including .sys, .exe, .dll, .htm, .jpg, .ini, etc) in the system by replacing the first 1099 bytes of these files with some junk codes, until the system becomes crash.

The infected files cannot be repaired.

More information can be found at this Sophos page.