Virus Name: Parasite
V Status: Rare
Discovery: January, 1992
Symptoms: .COM file growth; message & buzzing; warm reboots
Eff Length: 1,132 Bytes
Type Code: PNCK - Parasitic Non-Resident .COM Infector
Detection Method: ViruScan, F-Prot, Sweep, AVTK, ChAV,
IBMAV, NAV, NAVDX, VAlert, PCScan,
NShld, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N,
Removal Instructions: Delete infected files
The Parasite virus was received in January, 1992 from Canada.
Parasite is a non-resident, direct action infector of .COM
programs, including COMMAND.COM. It is based on the Sicilian
Mob virus, and indirectly on the Vienna virus.
When a program infected with Parasite is executed, the Parasite
virus will search the current directory for the first uninfected
.COM file. When it finds this uninfected .COM file, it will
then infect it.
Programs infected with the Parasite virus will have a file size
increase of 1,132 bytes. The virus will be located at the end of
the infected file. There will be no visible change to the file's
date and time in a DOS disk directory listing.
The following text strings are visible within the viral code in
Parasite infected programs:
"(C) 1991 by [NUKE] InterNat`nl Software Development"
"Parasite Virus, Released October 1991, Montreal, Canada"
"--> [NukE] H/A/P/C/T/V at its Best! <---"
"To John McAfee [I'll be BACK!]"
On approximately one out of every four infected program executions,
the Parasite virus will display the following message accompanied by
a loud buzzing on the system speaker:
"Parasite Virus! by Rock Steady [NukE] HP"
This message is not visible in infected programs as it is
encrypted. Once the message is displayed, the program the user was
attempting to execute will run.
Parasite will also occassionally cause a warm reboot of the system
when an infected program is executed.
Known variant(s) of Parasite are:
Parasite 2: Parasite 2 was received in February 1992, and is
originally from Montreal, Canada. It is a modified
version of the original Parasite virus, with many of
the text strings having been removed. The text strings
which remain are:
"ParaSite II - By: Rock Steady"
Each time a program infected with Parasite 2 is executed,
the virus will infect one .COM file in the current
directory, plus COMMAND.COM if it was not previously
infected. Programs infected with Parasite 2 will have a
file length increase of 901 bytes with the virus being
located at the end of the infected file. There will be
no change to the file's date and time in the DOS disk
directory listing. Systems infected with Parasite 2
may experience a "machine gun" noise being emitted on the
system speaker when infected programs are executed.
System hangs and intermittent boot failures may also
occur. The virus contains code to overwrite the C: drive
boot sector, directory, and FAT on Mondays, however this
code does not function properly.
Origin: Montreal, Canada February, 1992.
Parasite 2B: Similar to Parasite 2, the Parasite 2B variant is
two bytes larger than Parasite 2. It adds 903 bytes to
the .COM files it infects. The following text strings
can be found in all infected files:
"ParaSite IIB - By: Rock Steady"
It contains the same bug as Parasite 2, preventing it
from activating on Mondays and overwriting the hard disk.
Vengeance: Based on the Parasite virus, the Vengeance virus was
discovered in the United States in late May, 1992. It
infects one .COM file each time an infected program is
executed. Infected programs will have a file length
increase of 723 bytes with the virus being located at the
end of the file. The seconds in the file's time in the
DOS disk directory will have been set to 56, the virus's
infection marker. Programs infected with Vengeance will
contain the following text strings:
"*** Vengeance is ours! ***"
Origin: United States May, 1992.
Vengeance-B: Received in September, 1992, Vengeance-B is similar
to Vengeance described above. The seconds in the file's
time in the DOS disk directory will be set to 00
on all infected programs. Programs infected with
Vengeance-B will contain the following text strings:
Origin: Canada September, 1992.
Vengeance-C: Received in October, 1992, Vengeance-C is similar
to Vengeance described above, it has eight bytes which
Origin: Canada October, 1992.
See: Sicilian Mob Vienna