Not-586 Virus

Virus Name: Not-586 Aliases: V Status: Rare Discovered: February, 1993 Symptoms: .COM file growth; decrease in total system & available free memory Origin: USSR Eff Length: 586 Bytes Type Code: PRtCK - Parasitic Resident .COM Infector Detection Method: Sweep, AVTK, F-Prot, ViruScan, IBMAV, NAV, NAVDX, VAlert, PCScan, ChAV, Sweep/N, NShld, NProt, AVTK/N, NAV/N, IBMAV/N, Innoc, LProt Removal Instructions: Delete infected files General Comments: The Not-586 virus was submitted in February, 1993, and is originally from the USSR. Not-586 is a memory resident infector of .COM files, including COMMAND.COM. When the first Not-586 infected program is executed, this virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, moving interrupt 12's return. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 1,024 bytes. Interrupt 21 will be hooked by the virus in memory. Once memory resident, the Not-586 virus will infect .COM programs, including COMMAND.COM, when they are executed. Infected programs will have a file length increase of 586 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 Not-586 infected programs. It is unknown what Not-586 may do besides replicate.