Pila Virus

Virus Name: Pila Aliases: V Status: Rare Discovered: July, 1992 Symptoms: .COM & .EXE growth; decrease in total system & available free memory Origin: Unknwon Eff Length: 1,731 - 1,746 Bytes Type Code: PRhA - Parasitic Resident .COM & .EXE Infector Detection Method: ViruScan, IBMAV, AVTK, Sweep, F-Prot, NAV, PCScan, NAVDX, VAlert, ChAV, NShld, NProt, AVTK/N, Sweep/N, IBMAV/N, Innoc, NAV/N Removal Instructions: Delete infected files General Comments: The Pila virus was submitted in July, 1992. Its origin or point of isolation is unknown. Pila is a memory resident infector of .COM and .EXE programs, but not COMMAND.COM. The first time a program infected with the Pila virus is executed, this virus will install itself memory resident at the top of system memory but below the 640K DOS boundary. Interrupt 12's return will not be moved. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 2,016 bytes. Interrupt 21 will be hooked by Pila in memory. Once the Pila virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs will have a file length increase of 1,731 to 1,746 bytes with the virus being located at the end of the infected file. The program's date and time in the DOS disk directory listing will not be altered. The following text string is encrypted within the viral code, and is not visible in infected files: "pilapilapilapilapilapilapilapilapilapilapilapilapilapilapila" It is unknown if Pila does anything besides replicate, though it bears some similarity to the Year-1992 virus.