Virus Name: J&M
Aliases: Jimi, Jimmy
V Status: New
Discovery: December, 1997
Symptoms: decrease in total system & available free memory;
MBR altered; diskette boot sectors altered
Eff Length: N/A Bytes
Type Code: BRtX - Memory Resident Boot Sector & MBR Infector
Detection Method: ViruScan 3.14 3101+, NAV 3.11 9710+, NAVDX 4.0 9710+
Removal Instructions: FDisk /MBR or DOS SYS command, or use anti-viral
The J&M virus was received in December, 1997, though it has been
reported to be "in the wild" in Europe for some time. J&M is a
memory resident infector of the hard disk master boot record as
well as diskette boot sectors.
When a system is first booted with a J&M infected diskette, the
J&M virus will infect the system hard disk master boot record.
Then later, when the system is booted from the infected hard
drive, the virus will install itself memory resident. Total
system and available free memory will have decreased by 2,048
bytes, and interrupt 12's return will have been moved.
Once the J&M virus is memory resident, it will infect diskette
boot sectors when unwrite-protected diskettes are accessed on
the system. The virus contains the following unencrypted