889 Virus

Virus Name: 889 Aliases: V Status: Rare Discovery: March, 1993 Symptoms: .COM & .EXE growth; file date/time changes; decrease in total system & available free memory Origin: Unknown Eff Length: 889 - 903 Bytes Type Code: PRhA - Parasitic Resident .COM & .EXE Infector Detection Method: AVTK, F-Prot, Sweep, ViruScan, IBMAV, VAlert, NAV, NAVDX, PCScan, ChAV, Sweep/N, NShld, NProt, AVTK/N, IBMAV/N, Innoc, NAV/N Removal Instructions: Delete infected files General Comments: The 889 virus was submitted in March, 1993. Its origin or point of isolation is unknown. 889 is a memory resident infector of .COM and .EXE programs, but not COMMAND.COM. When the first 889 infected program is executed, the 889 virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, hooking interrupt 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 960 bytes. Interrupt 12's return will not be moved. Once the 889 virus is memory resident, it will infect .COM and .EXE programs, but not COMMAND.COM, when they are executed. Infected .COM programs will have a file length increase of 889 bytes with the virus being located at the end of the file. Infected .EXE programs will increase in size by 889 to 903 bytes with the virus at the end of the file. The infected program's date and time in the DOS disk directory listing will have been updated to the current system date and time when infection occurred. No text strings are visible within the viral code in infected programs. It is unknown what the 889 virus may do besides replicate.