Ah Virus

Virus Name: Ah Aliases: Tuesday, David-1173 V Status: Research Discovery: May, 1991 Symptoms: .COM file growth; decrease in total system & available free memory; system hangs; hard disk format; message Origin: Italy Eff Length: 1,173 Bytes Type Code: PRhC - Parasitic Resident .COM Infector Detection Method: ViruScan, F-Prot, Sweep, AVTK, NAV, NAVDX, IBMAV, VAlert, PCScan, ChAV, NShld, LProt, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N Removal Instructions: Delete infected files General Comments: The Ah, or Tuesday, Virus was received in May, 1991. Ah is based on the V1024 virus, its origin is Italy. Ah is a very buggy virus which infects .COM programs. When the first program infected with Ah is executed, Ah 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 decrease by 1,216 bytes. Interrupts 08 and 21 will be hooked by the virus. After Ah is memory resident, it will infect .COM programs over 1K in length when they are executed. Infected programs will increase in size by 1,173 bytes, though the file length increase will be hidden if Ah is resident. Their date and time in the DOS directory will appear to be unaltered, though if the program's original time was 12:00a, it will now be blank. The virus will be located at the beginning of infected programs. Systems infected with Ah will experience frequent system hangs. These hangs occur when the user attempts to execute a .COM program which is infected with Ah. They may also occur when the virus attempts to infect an uninfected program. System hangs occur so frequently with Ah that the virus is very noticeable. The Ah virus activates on Tuesdays, at which time it will attempt to format the first few tracks of the system hard disk. Programs infected with Ah can be easily identified as they will contain the following text strings: "(C) David Grant Virus Research 1991 PCVRF Disribuite this virus freely!!! ...ah...John...Fuck You!" Ah is believe to have been created by the same person as several other viruses from Italy, including Smack and Enigma. David Grant and the PCVRF had nothing to do with its creation. Known variant(s) of Ah are: Ah-B: Similar to the original virus, this variant will occassionally infect an .EXE program. It contains the same text strings as the original virus. Origin: Unknown October, 1992. See: Alfa V1024