Karlik Virus

Virus Name: Karlik Aliases: V Status: Rare Discovered: August, 1993 Symptoms: .COM & .EXE growth; decrease in total system & available free memory Origin: Unknown 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, LProt Removal Instructions: Delete infected files General Comments: 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.