Black Hawk Virus

Virus Name: Black Hawk Aliases: V Status: New Discovery: December, 1994 Symptoms: .COM file growth; file date/time seconds = "62"; beeping on December 25th; decrease in total system & available free memory Origin: United States Eff Length: 826 Bytes Type Code: PRhCK - Parasitic Resident .COM Infector Detection Method: ViruScan, F-Prot, AVTK, IBMAV, NAV, Sweep, NAVDX, VAlert, ChAV, PCScan, IBMAV/N, NShld, AVTK/N, Sweep/N, NAV/N, NProt, Innoc Removal Instructions: Delete infected files General Comments: The Black Hawk virus was received in December, 1994, and is from the United States. Black Hawk is a memory resident infector of .COM files, including COMMAND.COM. It activates when the virus becomes memory resident on December 25th of any year, at which time it will emit beeping on the system speaker. When the first Black Hawk 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 from DOS 3.30 will have decreased by 18,416 bytes. Interrupt 21 will be hooked by the virus in memory. Once the Black Hawk virus is memory resident, it will infect .COM programs when they are executed. Infected programs will have a file length increase of 826 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 appear to be altered, though the seconds field will have been set to "62", the infection marker for the virus. The following text string is encrypted within the viral code: "[NuKE] N.R.L.G. AZRAEL"