This is a dangerous memory resident parasitic virus. It hooks INT 9, 21h and writes itself to the end of COM and EXE files that are executed.
By using INT 9 (keyboard) the virus checks INT 1 (trace), and while tracing it displays the message:
IRANIAN VIRUS W.by ABBAS KUHKAN ALIABADI
and halt the computer.
The viruses also contain the text string:
Depending on the system timer "Abbas.5660" loads some font, and displays (persian?) messages.