This is a very dangerous memory resident encrypted parasitic virus. It hooks INT 21h and writes itself to the end of COM and EXE files that are executed. While executing a file with the name F77*.*, the virus deletes that file. On Mondays, the virus writes the following string to the end of the C:AUTOEXEC.BAT file:
@ECHO Y | FORMAT D:
On Tuesdays, the virus modifies the Interrupt Timer by writing to the timer ports. The virus also contains the internal text strings:
ANTI FORTRAN OF OVER-X
C:AUTOEXEC.BAT
