Virus Name: 1840
V Status: Rare
Discovery: July, 1991
Symptoms: .COM & .EXE file growth; TSR; Write protect errors
Eff Length: 1,838 - 1,891 Bytes
Type Code: PRsAK - Parasitic Resident .COM & .EXE Infector
Detection Method: ViruScan, AVTK, Sweep, F-Prot, ChAV,
NAV, IBMAV, NAVDX, VAlert, PCScan,
NShld, LProt, Sweep/N, Innoc, NProt, AVTK/N,
Removal Instructions: Delete infected files
The 1840 virus was isolated and submitted in July, 1991. Its point
of isolation is unknown. 1840 is a memory resident infector of .COM
and .EXE files, including COMMAND.COM.
The first time a program infected with 1840 is executed, the virus
will become memory resident as a low system memory TSR of 2,144
bytes. Interrupt 21 will be hooked by the virus in memory.
Once memory resident, 1840 will infect programs as they are executed.
If COMMAND.COM is executed, it will become infected. Infected
programs increase in size by 1,838 to 1,891 bytes. The virus will
be located at the end of the infected program.
Two text strings occur within the virus which can be found in
It is unknown if 1840 does anything besides replicate.