Virus Name: Crusher
V Status: Rare
Discovery: November, 1992
Symptoms: .EXE file growth; master boot sector altered; decrease in
total system & available free memory; cross-linking of files;
Origin: The Netherlands
Eff Length: 2,048 Bytes
Type Code: PRhEX - Parasitic Resident .EXE & Master Boot Sector Infector
Detection Method: ViruScan, Sweep, AVTK, NAV, NAVDX, VAlert, PCScan,
NShld, Sweep/N, AVTK/N, NAV/N, Innoc 4.0+
Removal Instructions: Delete infected files
The Crusher virus was submitted in November, 1992. It is from The
Netherlands. Crusher is a memory resident infector of the hard
disk master boot sector (partition table) and .EXE programs. It
employs some stealth techniques to avoid detection.
The first time a program infected with the Crusher virus is executed,
the Crusher virus will infect the system hard disk master boot
sector. It writes an unencrypted copy of the viral code to Side 0,
Cylinder 0, sectors 2 thru 5, and then alters the hard disk master
boot sector so that this code will be executed the next time the
system is booted from the hard disk. It does not become memory
resident at this time.
The next time the system is booted from the system hard disk, the
Crusher 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 2,064 bytes. Interrupt 21 will be hooked by Crusher in memory.
Once the Crusher virus is memory resident, it will infect .EXE
programs when they are executed. Infected programs will have a file
length increase of 2,048 bytes, though the file length increase will
be hidden when the virus is active in memory. The file's date and
time in the DOS disk directory listing will not be altered. The
following text strings are encrypted within the viral code:
"You are damned"
"Bit Addict / Trident"
The Crusher virus will occassionally display the above text when
it is memory resident. Infected systems will also experience
cross-linking of files.