Virus Name: NoBock
V Status: Rare
Discovered: January, 1991
Symptoms: .COM growth; message and system halt
Eff Length: 440 Bytes
Type Code: PNC - Parasitic Non-Resident .COM Infector
Detection Method: ViruScan, F-Prot, Sweep, AVTK, ChAV,
IBMAV, NAV, NAVDX, VAlert, PCScan,
NShld, LProt, Sweep/N, Innoc, NProt, AVTK/N,
Removal Instructions: Delete infected files
The NoBock virus was discovered in Europe in January, 1991. NoBock
is a non-resident direct action infector of .COM files.
When a program infected with NoBock is executed, the virus will
check the system date. If the date is other than between January
1, 1980 and September 30, 1980, it will display the following
message and halt the system, not infecting any other files:
"No Bock today Error, System halted!"
The drive will be left spinning.
If the system clock is set to a date between January 1, 1980 and
September 30, 1980, NoBock may infect one other .COM file in the
current drive and directory when an infected program is executed.
The virus, however, does not infect another program each time an
infected program is executed during this period of time.
NoBock infected files will have a file length increase of 440 bytes,
the virus will be located at the end of the infected program.
NoBock is an encrypted virus, and the above message cannot be viewed
within infected files.