Virus Name: Mercenary
V Status: Rare
Discovered: September, 1993
Symptoms: .COM file growth;
decrease in total system & available free memory
Eff Length: 854 Bytes
Type Code: PRhCK - Parasitic Resident .COM Infector
Detection Method: ViruScan, IBMAV, Sweep, NAV, AVTK, F-Prot,
NAVDX, VAlert, PCScan, ChAV,
AVTK/N, NShld, Sweep/N, NAV/N, NProt, AVTK/N, IBMAV/N,
Removal Instructions: Delete infected files
The Mercenary virus was submitted in September, 1993. Its origin
or point of isolation is unknown. Mercenary is a memory resident
infector of .COM programs, including COMMAND.COM.
When the first Mercenary infected program is executed, this virus
will install itself memory resident at the top of system memory
but below the 640K DOS boundary, not moving interrupt 12's return.
Total system and available free memory, as indicated by the DOS CHKDSK
program, will have decreased by 7,040 bytes. Interrupt 21 will be
hooked by Mercenary in memory.
Once the Mercenary virus is memory resident, it will infect .COM
programs, including COMMAND.COM, when they are executed. Infected
files will have a file length increase of 854 bytes with the virus
being located at the end of the file. The program's date and time
in the DOS disk directory listing will not be altered. The following
text strings are encrypted within the Mercenary viral code, and are
not visible within infected programs:
"Mercenry Virii V.1 written by Lupus Yonderboy"
"Greets to all of Phalcon / Skism (who don't know i exist)"
"Welcome to the wonderful world of VIRII"
"You are now in possession of the Mercenry Virii."
"By Lupus Yonderboy"
"Chaos Mr. Who."
"That is our mode and modus"
"Hail to the Succubi"