| Description:
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Details
KbrBug.895
These are harmless memory resident encrypted parasitic viruses. They hook INT 1, 3, 1Ch, ACh and write themselves to the end of COM (except COMMAND.COM), EXE and OVL files. The viruses make a patch of original INT 21h handler - they insert interrupt call ACh into original INT 21h code, and set INT ACh vector to the address of the virus body.
These viruses do not infect the files for a few days after infection of the system. Periodically they call the trigger routine that jokes with the keyboard by changing the keyboard buffer address and filling the buffer with a "dust".
"KbrBug.895" is not such complex: it hooks only INT 1Ch, 21h and does not infect EXE files. Sometimes this virus exchanges the digits '0' to '9' on the screen.
"KbrBug.2662" also hooks INT 8, 10h and manifests itself with some video effects. |
