Casteggio Virus

Virus Name: Casteggio Aliases: V Status: Rare Discovery: October, 1992 Symptoms: .COM & .EXE growth; decrease in total system & available free memory Origin: Casteggio, Italy Eff Length: 2,881 - 2,900 Bytes Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector Detection Method: AVTK, F-Prot, ViruScan, Sweep, IBMAV, NAV, NAVDX, VAlert, PCScan, ChAV, NShld, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N, LProt Removal Instructions: Delete infected files General Comments: The Casteggio virus was received from Italy in October, 1992 after its isolation in the public domain in Casteggio, Italy. Casteggio is a memory resident infector of .COM and .EXE programs, including COMMAND.COM. When the first program infected with the Casteggio virus is executed, the Casteggio virus will install itself memory resident at the top of system memory but below the 640K DOS boundary. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 3,008 bytes. Interrupts 1C and 21 will be hooked. Once the Casteggio virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs will have a file length increase of 2,881 to 2,900 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 Casteggio does besides replicate.