Which of the following countermeasures is not appropriate for war dialing attacks?

A.
Monitoring and auditing for such activity.

B.
Disabling call forwarding.

C.
Making sure only necessary phone numbers are made public.

D.
Using completely different numbers for voice and data accesses.

Explanation:
War dialing, or scanning, has been a common activity in the computer underground and computer
security industry for decades. Hollywood made war dialing popular with the 1983 movie, War
Games, in which a teenager searching for a videogame company ultimately uncovers a government
nuclear war warning system. The act of war dialing is extremely simple – a host computer dials a
given range of telephone numbers using a modem. Every telephone number that answers with a
modem and successfully connects to the host is stored in a log. Disabling call forwarding is not a
useful countermeasure because it’s the attacker machine the one who connects to the attacked
system and forwarding is not an issue inside the attack. Answer A, C and D can be used as
countermeasures to harder the war dial attack.