Here a quick nice little virus from our boyz up north.
V Status: Rare
Discovered: July, 1990
Symptoms: .COM & .EXE growth; decrease in system and free memory;
hard disk errors in the case of extreme infections
Origin: Ontario, Canada
Eff Length: 512 Bytes
Type Code: PRtAK - Parasitic Encrypted Resident .COM & .EXE Infector
Detection Method: ViruScan V66+, Pro-Scan 2.01+, NAV
Removal Instructions: SCAN /D, or Delete infected files
General Comments:
The Ontario Virus was isolated by Mike Shields in Ontario, Canada
in July, 1990. The Ontario virus is a memory resident infector of
.COM, .EXE, and overlay files. It will infect COMMAND.COM.
The first time a program infected with the Ontario Virus is executed,
it will install itself memory resident above the top of system memory
but below the 640K DOS boundary. Total system memory and free memory
will be decreased by 2,048 bytes. At this time, the virus will
infect COMMAND.COM on the C: drive, increasing its length by 512 bytes.
Each time an uninfected program is executed on the system with the
virus memory resident, the program will become infected with the viral
code located at the end of the file. For .COM files, they will
increase by 512 bytes in all cases. For .EXE and overlay files, the
file length increase will be 512 - 1023 bytes. The difference in
length for .EXE and overlay files is because the virus will fill out
the unused space at the end of the last sector of the uninfected file
with random data (usually a portion of the directory) and then append
itself to the end of the file at the next sector. Systems using
a sector size of more than 512 bytes may notice larger file increases
for infected files. Infected files will always have a file length
that is a multiple of the sector size on the disk.
In the case of extreme infections of the Ontario Virus, hard disk
errors may be noticed.
Ontario uses a complex encryption routine, and a simple identification
string will not identify this virus.