A&A Virus

Virus Name: A&A Aliases: V Status: Rare Discovery: February, 1993 Symptoms: .COM file growth; file date/time changes Origin: USSR Eff Length: 506 Bytes Type Code: PRxC - Parasitic Resident .COM Infector Detection Method: Sweep, AVTK, F-Prot, ViruScan, NAV, IBMAV, NAVDX, VAlert, PCScan, ChAV, Sweep/N, NShld, AVTK/N, NProt, NAV/N, IBMAV/N, Innoc, LProt Removal Instructions: Delete infected files General Comments: The A&A virus was submitted in February, 1993, and is from the USSR. A&A is a memory resident infector of .COM programs, but not COMMAND.COM. It uses a tunneling technique to avoid detection by anti-viral monitoring programs. When the first A&A infected program is executed, the A&A virus will install itself memory resident in a "hole" in low allocated system memory, hooking interrupt 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will not be altered. Once the A&A virus is memory resident, it will infect .COM programs other than COMMAND.COM when they are executed. Infected programs will have a file length increase of 506 bytes with the virus being located at the beginning of the file. The program's date and time in the DOS disk directory listing will have been updated to the current system date and time when infection occurred. The following text string can be found within the viral code in all A&A infected programs: "{A&A}" It is unknown what A&A may do besides replicate.