Virus Name: Finnish-709
Aliases: 709, Swedish-709
V Status: Rare
Discovered: September, 1991
Symptoms: .COM file growth; decrease in total system and available free
Eff Length: 709 Bytes
Type Code: PRhCK - Parasitic Resident .COM Infector
Detection Method: ViruScan, AVTK, Sweep, F-Prot, ChAV,
NAV, IBMAV, NAVDX, VAlert, PCScan,
NShld, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N,
Removal Instructions: Delete infected files
The Finnish-709 virus was submitted in September, 1991, by
Mikael Larsson of Virus Help Centre, Sweden. It is originally from
Finland. Finnish-709 is a memory resident infector of .COM files,
The first time a program infected with Finnish-709 is executed,
this virus will become 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 2,560 bytes. Interrupt 12's return will not have been
moved. Interrupts 1C and 21 will be hooked by the virus in memory.
Once memory resident, Finnish-709 will infect .COM programs,
including COMMAND.COM, when they are opened or executed. Infected
.COM programs increase in size by 709 bytes. The virus will be
located at the end of infected files. There will be no change in
the file's date and time in the DOS disk directory.
Finnish-709 doesn't do anything besides replicate.
Known variant(s) of Finnish-709 are:
Finnish-357: Based on the Finnish-709 virus described above,
this variant is a re-written, smaller version. Its
size in memory is 2,048 bytes, hooking interrupt 21.
It infects .COM programs, including COMMAND.COM,
when they are executed. Infected programs will have
a file length increase of 357 bytes with the virus
being located at the end of the file. The file's
date and time in the DOS disk directory listing will
have been updated to the current system date and time.
Like the original, it doesn't do anything besides
Origin: Finland November, 1992.