Virus Name: Grace
V Status: New
Discovered: January, 1996
Symptoms: .COM & .EXE growth; decrease in available free memory;
Eff Length: 1,346 or more Bytes
Type Code: PRhA - Parasitic Resident .COM & .EXE Infector
Detection Method: NAV, NAVDX, AVTK, ViruScan, IBMAV, F-Prot, ChAV,
NAV/N, AVTK/N, NShld, IBMAV/N, Innoc
Removal Instructions: Delete infected files
The Grace or Grace.1346 virus was received in January, 1996. Its
origin or point of isolation is unknown. Grace is a memory resident
fast infector of .COM and .EXE files, but not COMMAND.COM.
When the first Grace 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. Available
free memory, as indicated by the DOS CHKDSK program from DOS 5.0,
will have decreased by 5,120 bytes. Interrupt 21 will be hooked by
the virus in memory.
Once the Grace virus is memory resident, it will infect .COM and
.EXE files when they are executed, opened, or copied. Infected .COM
files will have a file length increase of 1,346 bytes with the virus
being located at the end of the file. .EXE files will increase in
size by more than 1,346 bytes, and the virus will be located
somewhere between the middle and the end of the file. In both cases,
the program's date and time in the DOS disk directory listing will
not be altered. The following text strings are visible within the
viral code in all infected programs:
"-[Grace] by T„L”N 94-"
"You make me sick I make viruses"
"Have a nice $piss-up!"
System hangs may occur when small .COM and .EXE files are executed
with the virus memory resident.