Manzon Virus

Virus Name: Manzon Aliases: V Status: New Discovered: January, 1996 Symptoms: .COM & .EXE growth; file date/time changes; decrease in available free memory Origin: Unknown Eff Length: 1,430 - 1,484 Bytes (Approximate) Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector Detection Method: AVTK, NAV, NAVDX, IBMAV, ViruScan, F-Prot, PCScan, ChAV, NAV/N, IBMAV/N, NShld, AVTK/N, Innoc 4.0+ Removal Instructions: Delete infected files General Comments: The Manzon virus was received in January, 1996. Its origin or point of isolation is unknown. Manzon is a memory resident infector of .COM and .EXE files, including COMMAND.COM. When the first Manzon 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. Available free memory, as indicated by the DOS CHKDSK program from DOS 5.0, will have decreased by 1,744 bytes. Interrupt 21 will be hooked by the virus in memory. Once the Manzon virus is memory resident, it will infect .COM and .EXE files, including COMMAND.COM, when they are executed. Infected files will have a file length increase of approximately 1,430 to 1,484 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 have been updated to the current system date and time when infection occurred. The following text string is encrypted within the viral code: "MANZON (c) Sgg1F5PZ" It is unknown what the Manzon virus may do besides replicate.