Virus Name: Madwill.B
V Status: New
Discovered: January, 1995
Symptoms: .COM & .EXE growth; DOS CHKDSK file allocation errors;
decrease in total system & available free memory;
file date/time decade set to "2"
Eff Length: 2,400 Bytes
Type Code: PRhA - Parasitic Resident .COM & .EXE Infector
Detection Method: F-Prot, AVTK, IBMAV, Sweep, ViruScan, NAV,
NAVDX, VAlert, ChAV,
AVTK/N, IBMAV/N, Sweep/N, NProt, NShld, NAV/N, Innoc 4.0+
Removal Instructions: Delete infected files
The Madwill.B virus was received in January, 1995. It appears to
be from Moscow. Madwill.B is a memory resident semi-stealth fast
infector which infects .COM and .EXE files, but not COMMAND.COM.
It is unknown what it does besides replicate.
When the first Madwill.B 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 2,672 bytes. Interrupts
21 and 93 will be hooked by the virus in memory.
Once the Madwill.B virus is memory resident, it will infect .COM
and .EXE files, other than very small ones and COMMAND.COM, when
they are executed, opened, or copied. Infected files will increase
in size by 2,400 bytes, though the file length increase will be
hidden when the virus is memory resident. The virus will be located
at the end of the file. The program's date and time in the DOS disk
directory listing will be altered so that the decade in the file
date is set to "2". The following text strings are visible within
the viral code in all Madwill.B infected programs:
"This program requires MS-DOS version 3.30 or later."
"The Stainless Steel TechRat, v1.1, 28.05.94,
(C) 1993-94 by MadWill Stealth Labs, Moscow, Russia"
"WYSINWYG (What you see is NOT what you get)"
"Thanks to H. Harrison"
"Story 1 of 7 : The Stainless Steel TechRat is Born"
The DOS CHKDSK program will return file allocation errors on all
infected files when the Madwill.B virus is memory resident.