Page 25 - DCAP309_INFORMATION_SECURITY_AND_PRIVACY

Unit 2: Threats

Brute-force: It is method in which a hacker tries to guess a password by repeatedly entering in Notes
new combinations of words and phrases compiled from a dictionary to steal the password.
Developing difficult to guess usernames and passwords can prevent it.
Packet sniffers: Packet sniffers are the technique used to capture data streams over a network to
obtain sensitive data like usernames, passwords, credit card numbers, etc. Thus, packet sniffers
are more malicious forms of threats to the network security. Packet sniffers monitor and record
details that are coming from and going to a computer over a compromised network. To get
access to a network, packet sniffer use honeypots. They are simply unsecured wi-fi access points
that hackers create to trap users who are using them. Making users aware about the threat of
packet sniffers is best prevention policy. Falling to packet sniffers technique will lead to
compromise with sensitive network data. In addition, the user should use a variety of different
sign on names and passwords to access various levels of network security. This helps at the
instance when login information is compromised, the damage can at least be limited in scope.

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Caution A user should be aware not to access the Internet through an unsecured connection.
IP-spoofing: Like honeypots, IP spoofing involves the interception of data packets by a computer
successfully pretending to be a trusted server/resource.

2.3.6 Zombie Computers and Botnets

‘Zombie’ computer is a computer under seize of a spammer who has infected the computer
attached to a network with malware so that it acts as a tool of a spammer by silently sending out
thousands of emails from the owner’s email address. Thus, an innocent user’s computer sends
thousands of spam messages without the knowledge of the user. The spammers organize zombie
computers into small groups called ‘botnets’. These ‘botnets’ then transmits spam including
phishing attempts, viruses and worms.

Task What are Zombie computers? Discuss.

Did u know? The botnets normally send spamming and phishing attacks.

2.3.7 Denial-of-Service Attack (DoS)

Denial-of-Service attack (DoS) is an attack method to deny the access to webpages of a website or
network to the legitimate users.

Self Assessment

Fill in the blanks:
6. The term ....................... refers specifically to malware inserting malicious code into existing
documents or programs.

7. It is often observed that organizations block free download software to prevent themselves
from the attack of ....................... .

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