Bad-389 Virus

Virus Name: Bad-389 Aliases: V Status: Rare Discovery: March, 1993 Symptoms: .COM file growth; file date/time changes; TSR Origin: Unknown Eff Length: 389 Bytes Type Code: PRsCK - Parasitic Resident .COM Infector Detection Method: AVTK, F-Prot, Sweep, ViruScan, IBMAV, NAV, NAVDX, VAlert, PCScan, ChAV, Sweep/N, Innoc, NShld, AVTK/N, NProt, IBMAV/N, NAV/N Removal Instructions: Delete infected files General Comments: The Bad-389 virus was submitted in March, 1993. Its origin or point of isolation is unknown. Bad-389 is a memory resident infector of .COM programs, including COMMAND.COM. When the first Bad-389 infected program is executed, the Bad-389 virus will install itself memory resident as a low system memory TSR of 544 bytes. Interrupt 21 will be hooked by the virus. Bad-389 cannot determine when it is already memory resident, so it will reinfect memory each time an infected program is executed, taking up an additional 544 bytes of memory. Once memory resident, the Bad-389 virus will infect .COM programs, including COMMAND.COM, when they are executed. Infected programs will have a file length increase of 389 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 set to the current system date and time when infection occurred. The following text string is visible within the viral code in all Bad-389 infected programs: "Bad command or file name"