Cavaco Virus

Virus Name: Cavaco Aliases: Cavaco.1470 V Status: New Discovery: January, 1996 Symptoms: .COM & .EXE growth; decrease in available free memory Origin: Portugal Eff Length: 1,470 Bytes Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector Detection Method: NAV, NAVDX, IBMAV, ViruScan, VAlert, AVTK, F-Prot, ChAV, PCScan, AVTK/N, NAV/N, IBMAV/N, NShld, Innoc Removal Instructions: Delete infected files General Comments: The Cavaco virus was received in January, 1996. It appears to be from Portugal. Cavaco is a memory resident infector of .COM and .EXE files, including COMMAND.COM. When the first Cavaco 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. Available free memory, as indicated by the DOS CHKDSK program from DOS 5.0, will have decreased by 1,760 bytes. Interrupt 21 will be hooked by the virus in memory. Also at this time, the virus will infect the copy of COMMAND.COM located in the C: drive root directory if it was not previously infected by the virus. Once the Cavaco virus is memory resident, it will infect .COM and .EXE files when they are executed. Infected programs will have a file length increase of 1,470 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. The following text strings are visible within the viral code: "c:\command.com" "Do you like this Screen Saver ?" "Cavaco - A virus created by The Portuguese Government" It is unknown that the Cavaco virus may do besides replicate.