Virus Name: Karlik
V Status: Rare
Discovered: August, 1993
Symptoms: .COM & .EXE growth;
decrease in total system & available free memory
Eff Length: 1,666 Bytes
Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector
Detection Method: F-Prot, IBMAV, Sweep, ViruScan, NAV, AVTK,
NAVDX, VAlert, PCScan, ChAV,
NShld, Sweep/N, NAV/N, NProt, AVTK/N, IBMAV/N, Innoc,
Removal Instructions: Delete infected files
The Karlik virus was submitted in August, 1993. Its origin or point
of isolation is unknown. Karlik is a memory resident infector of
.COM and .EXE programs, including COMMAND.COM.
When the first Karlik infected program is executed, this virus will
install itself memory resident at the top of system memory but below
the 640K DOS boundary, not moving interrupt 12's return. Total
system and available free memory, as indicated by the DOS CHKDSK
program, will have decreased by 1,808 bytes. Interrupts 08 and 21
will be hooked by Karlik in memory.
Once memory resident, the Karlik virus will infect .COM files, and
some .EXE files, when they are executed. Infected programs will have
a file length increase of 1,666 bytes with the virus being located
at the end of the file. The program's date and time in the DOS disk
directory listing will not be altered. No text strings are visible
within the viral code in infected programs.
It is unknown what Karlik does besides replicate.