CPSU-2535 Virus

Virus Name: CPSU-2535 Aliases: Protecto-2535 V Status: Rare Discovery: February, 1993 Symptoms: .COM & .EXE growth; decrease in total system & available free memory Origin: USSR Eff Length: 2,535 Bytes Type Code: PRtA - Parasitic Resident .COM & .EXE Infector Detection Method: F-Prot, ViruScan, NAV, Sweep, AVTK, IBMAV, NAVDX, VAlert, PCScan, ChAV, NShld, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N, LProt Removal Instructions: Delete infected files General Comments: The CPSU-2535 virus was submitted in February, 1993, and is from the USSR. This virus is a memory resident infector of .COM and .EXE programs, but not COMMAND.COM. When the first CPSU-2535 infected program is executed, the CPSU-2535 virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, moving interrupt 12's return. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 3,088 bytes. Interrupt 21 will be hooked by CPSU-2535 in memory. Once the CPSU-2535 virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs will have a file length increase of 2,535 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 in infected programs. It is unknown what CPSU-2535 does besides replicate. See: Protecto