Zipper contains several bugs which might corrupt the infected files.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
This is a simple virus which stays resident in memory and infects COM and EXE files when they are accessed. \COMMAND.COM and \DOS\FORMAT.COM are infected on the first execution.
If you run PKZIPFIX against an infected COM or EXE file, it will create a PKFIXED.ZIP, which contains an assembly source file called ZIPPER.ASM.
The virus contains this text, which is never displayed:>>*>> Use PKUNZIP *.EXE immediately! <<*<<