Virus Name: 1784
V Status: Rare
Discovery: November, 1993
Symptoms : .COM & .EXE growth;
decrease in total system & available free memory
Eff Length: 1,784 Bytes
Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector
Detection Method: F-Prot, ViruScan, IBMAV, Sweep, AVTK, NAV,
NAVDX, VAlert, PCScan, ChAV,
NShld, Sweep/N, AVTK/N, NProt, Innoc, IBMAV/N, NAV/N,
Removal Instructions: Delete infected files
The 1784 virus was received in November, 1993. Its origin or point
of isolation is unknown. This virus is a memory resident infector
of .COM and .EXE programs, including COMMAND.COM.
When the first 1784 infected program is executed, the 1784 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 2,304 bytes. Interrupt 21 will be
hooked by the virus in memory. Also at this time, the virus will
infect COMMAND.COM if it was not previously infected.
Once the 1784 virus is memory resident, it will infect .COM and .EXE
programs when they are executed or opened, but not when they are
copied. Infected programs will have a file length increase of 1,784
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. No text strings are visible within the viral code.
It is unknown what 1784 does besides replicate.