Datasheet

Book IX
Chapter 1
Fundamentals
of Security
1047
Understanding Physical Security
Figure 1-3:
Using
NetBus
to control
a user’s
computer.
Worm
A worm is a virus that does not need to be activated by someone open-
ing the file. The worm is self-replicating, meaning that it spreads itself from
system to system, infecting each computer. To protect against a worm, you
should install a firewall. A firewall is a piece of software or hardware that
prevents someone from entering your system.
Logic bomb
A logic bomb is malicious software that could run every day, but the soft-
ware was designed to wreak havoc on your system on a certain date and
time. The scary thing about logic bombs is that they seem like useful soft-
ware until the day the programmer decides it will become malicious!
To protect against malicious software such as a virus, Trojan horse, worm,
and a logic bomb you should use a firewall and keep your virus definitions
up-to-date.
Understanding Physical Security
You should implement security in many places, and one of the most over-
looked areas is physical security. Physical security has nothing to do with
software; rather, it covers how you protect your environment and systems
by making sure that a person cannot physically access the system. For
example, many companies use a numeric keypad to secure entrance to a
facility. To get into the facility, users must enter a valid combination to open
the door.
Another example of physical security is the server room. Most server room
doors are locked with a numeric padlock or a key. Higher-security server
rooms sometimes even require fingerprint or retinal scans from anyone
trying to enter the room. The benefit of locking your servers in the server
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