Vicious Virus

Virus Name: Vicious Aliases: Vicious.918 V Status: New Discovered: October, 1994 Symptoms: .COM & .EXE growth; file date/time seconds = "40"; decrease in total system & available free memory Origin: Sweden Eff Length: 918 or 943 Bytes Type Code: PRAK - Parasitic Resident .COM & .EXE Infector Detection Method: F-Prot, AVTK, IBMAV, ViruScan, Sweep, NAV, NAVDX, VAlert, PCScan, AVTK/N, Sweep/N, IBMAV/N, NShld, NAV/N, LProt Removal Instructions: Delete infected files General Comments: The Vicious or Vicious.918 virus was received in October, 1994 and appears to be from Sweden. Vicious is a memory resident fast infector of .COM and .EXE programs, including COMMAND.COM. When the first Vicious 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 2,016 bytes. Interrupt 21 will be hooked by the virus in memory. Once the Vicious virus is memory resident, it will infect .COM and .EXE programs when they are executed, opened, copied, or when a DOS DIR command is issued. Infected .COM programs will have a file length increase of 918 bytes while infected .EXE programs will increase in size by 943 bytes. In both cases the virus will be located at the end of the file. The program's date and time in the DOS disk directory listing will not appear to be altered, though the seconds field will have been set to "40". The following text strings are encrypted within the viral code: "*.COM *.EXE" "[Vicious!] MnemoniX"