ISC Exam Questions

What is the most likely cause of the account lockouts?

Mark works as a Network Administrator for NetTech Inc. The company has a Windows 2000
domain-based network. Users report that they are unable to log on to the network. Mark finds that
accounts are locked out due to multiple incorrect log on attempts. What is the most likely cause of
the account lockouts?

A.
Spoofing

B.
Brute force attack

C.
SYN attack

D.
PING attack

Explanation:
Brute force attack is the most likely cause of the account lockouts. In a brute force
attack, unauthorized users attempt to log on to a network or a computer by using multiple possible
user names and passwords. Windows 2000 and other network operating systems have a security
feature that locks a user account if the number of failed logon attempts occur within a specified
technique that makes a transmission appear to have come from an authentic source by forging the
IP address, email address, caller ID, etc. In IP spoofing, a hacker modifies packet headers by
using someone else’s IP address to hide his identity. However, spoofing cannot be used while
surfing the Internet, chatting on-line, etc. because forging the source IP address causes the
the TCP/IP protocol. It is a protocol-level attack that can render a computer’s network services
computer repeatedly sends ICMP echo requests to another computer, it is known as a PING
attack.