Virus Name: 439
V Status: Rare
Discovery: August, 1992
Symptoms: .COM file growth; decrease in total system & available free
Eff Length: 439 Bytes
Type Code: PRhCK - Parasitic Resident .COM Infector
Detection Method: F-Prot, Sweep, ViruScan, IBMAV, AVTK, NAV,
NAVDX, VAlert, PCScan, ChAV,
NShld, Sweep/N, Innoc, NProt, AVTK/N, LProt, NAV/N,
Removal Instructions: Delete infected files
The 439 virus was received in August, 1992. It is originally from
Poland. 439 is a memory resident infector of .COM programs,
The first time a program infected with the 439 virus is executed,
the 439 virus will install itself memory resident at the top of
system memory but below the 640K DOS boundary. Total system and
available free memory, as indicated by the DOS CHKDSK program,
will have decreased by 2,064 bytes. Interrupt 21 will be hooked
by the virus in memory.
Once the 439 virus is memory resident, it will infect .COM programs,
including COMMAND.COM, when they are executed or opened. Infected
programs will have a file length increase of 439 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 439 virus doesn't appear to do anything besides replicate.
Known variant(s) of 439 are:
439-B: Functionally equivalent to the original virus, 439-B is
a minor variant. A couple bytes differ from the original.
Origin: Poland September, 1992.