Explosion Virus

Virus Name: Explosion Aliases: Neznamy V Status: Rare Discovered: June, 1993 Symptoms: .COM & .EXE growth; decrease in total system & available free memory Origin: Unknown Eff Length: 1,000 Bytes Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector Detection Method: ViruScan, F-Prot, AVTK, IBMAV, Sweep, NAV, NAVDX, VAlert, PCScan, ChAV, NShld, AVTK/N, Sweep/N, NProt, Innoc, IBMAV/N, NAV/N, LProt Removal Instructions: Delete infected files General Comments: The Explosion virus was received in June, 1993. Its origin or point of isolation is unknown. Explosion is a memory resident infector of .COM and .EXE programs, including COMMAND.COM. When the first Explosion 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 1,008 bytes. Interrupt 21 will be hooked by Explosion in memory. Once the Explosion virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs will have a file length increase of 1,000 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 be altered. No text strings are visible within the viral code. It is unknown what Explosion may do besides replicate.