Yafo Virus

Virus Name: Yafo Aliases: Mog, Macabi V Status: Rare Discovered: May, 1992 Symptoms: .COM file growth; file date/time changed to 2-15-91 12:00a; message displayed Origin: Unknown Eff Length: 328 Bytes Type Code: PNCK - Parasitic Non-Resident .COM Infector Detection Method: ViruScan, Sweep, F-Prot, AVTK, ChAV, IBMAV, NAV, NAVDX, VAlert, PCScan, NShld, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N, LProt Removal Instructions: Delete infected files General Comments: The Yafo, or Mog, virus was submitted in May, 1992. Its origin or point of isolation is unknown. Yafo is a non-resident, direct action infector of .COM programs, including COMMAND.COM. When a program infected with the Yafo virus is executed, the Yafo virus will infect all .COM programs located in the current directory. If COMMAND.COM is located in this directory, it will be infected. Once the virus has infected all of the .COM files in the directory, it will display the following message and then the host program will continue to execute: "Maccabi Yafo Alufa !!!" Programs infected with the Yafo virus will have a file length increase of 328 bytes with the virus being located at the end of the file. The file's date and time in the DOS disk directory listing will have been altered to 2-15-91 12:00a. The message displayed by the virus is not visible within the viral code in infected programs as it is encrypted. Once text string is visible within the viral code in infected programs: "*.COM"