Virus.DOS.Raptor.1800 is a virus that runs on MS-DOS.
This virus has 4 variants :
Raptor.a is a relatively harmless, memory resident parasitic virus. This virus hooks INT 21h, and writes itself to the end of EXE files that are loaded into the memory or opened. On the 13th of any month, it hooks INT 1Ch also, and runs itself as a video effect. If the date and month correspond by number (January 1st, February 2nd,...), this virus decrypts and displays a message, then reboots the computer:
The Raptor virus version 1.5 Copyright 3.12.1993 - Hacker club Brno - Czech republic Don`t panic!! This virus doesn`t destroy data! I am most kindly virus!! I should inform you that soon comes Raptor2.0 with special sealth systems! You can be sure that Raptor2 will be totally untouchable!