Virus.DOS.Cerberus.1353 or Cerberus is a virus that runs on MS-DOS.
Cerberus is a memory resident parasitic virus. On execution it copies its body into the memory area at the address 8000:0100 without correction of the MCB blocks, which cause the computer to hang. It then hooks onto INT 21h and INT 28h, in which on opening the files it sets its own internal flag, then on an INT 28h call it checks that flag and if it is on, the virus infects .COM files and writes itself to the beginning of the file.
After 80 infections it draws the moving dog's muzzle.