Sleepwalker Virus

Virus Name: Sleepwalker Aliases: V Status: Rare Discovered: September, 1993 Symptoms: .COM file growth; decrease in total system & available free memory; file time changed to 10:47a Origin: Australia Eff Length: 1,268 - 1,282 Bytes Type Code: PRhCK - Parasitic Resident .COM Infector Detection Method: AVTK, F-Prot, IBMAV, Sweep, ViruScan, NAV, NAVDX, VAlert, PCScan, ChAV, AVTK/N, Sweep/N, NShld, NProt, IBMAV/N, Innoc, NAV/N Removal Instructions: Delete infected files General Comments: The Sleepwalker virus was submitted in September, 1993, and is from Australia. Sleepwalker is a memory resident virus which infects .COM programs, including COMMAND.COM. When the first Sleepwalker infected program is executed, this virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, hooking interrupts 1C and 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 1,552 bytes. Interrupt 12's return will not have been moved. Once the Sleepwalker virus is memory resident, it will infect .COM programs, including COMMAND.COM, when they are executed or opened. Infected programs will have a file length increase of 1,268 to 1,282 bytes with the virus being located at the end of the file. The file's date in the DOS disk directory listing will not be altered, but the file time will have been altered to "10:47a". The following text strings are visible within the Slime viral code: "STAC" "Sleepwalker. (c) OPTUS 1993." It is unknown what Sleepwalker does besides replicate.