Virus Name: Pila
V Status: Rare
Discovered: July, 1992
Symptoms: .COM & .EXE growth; decrease in total system & available
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
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:
It is unknown if Pila does anything besides replicate, though it
bears some similarity to the Year-1992 virus.