Virus Name: MZV
V Status: New
Discovery: January, 1996
Symptoms: .COM file growth; decrease in available free memory
Eff Length: 333 Bytes
Type Code: PRhCK - Parasitic Resident .COM Infector
Detection Method: ChAV, F-Prot, AVTK, IBMAV, ViruScan, NAV, NAVDX,
Innoc, AVTK/N, IBMAV/N, NShld, NAV/N
Removal Instructions: Delete infected files
The MZV or MZV.333 virus was received in January, 1996. Its origin
or point of isolation is unknown. MZV is a memory resident
infector of .COM files, including COMMAND.COM.
When the first MZV infected program is executed, this virus will
install itself memory resident at the top of system memory but
below the 640K DOS boundary, not moving interrupt 12's return.
Available free memory, as indicated by the DOS CHKDSK program from
DOS 5.0, will have decreased by 1,024 bytes. Interrupt 21 will be
hooked by the virus in memory.
Once the MZV virus is memory resident, it will infect .COM files,
including COMMAND.COM, when they are executed. Infected files will
have a file length increase of 333 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 following
text string is visible within the viral code:
"MZV 2 !!!"