Page 145 - DCAP516_COMPUTER_SECURITY

Unit 11: Threats in Network

11.3 Summary Notes

There are many different types of threats to network systems such as viruses, bombs,
worms, Trojan horses, etc.

Buffer overrun, input overflow and unchecked buffer overflow is probably the most
common way of breaking into a computer.

Section 66 of the Information Technology Act, 2000 defines the offence of hacking. The Act
has taken a unique approach to defining the term ‘hacking’. Hacking is usually understood
to be unauthorized access of computer systems and networks.
Packet Sniffing is a technology used by hackers to intercept and decrypt the data packets
flowing on a computer network.

Trojan horse program pretends to do one thing while actually doing something completely
different.

Password cracking means decrypting a password or bypassing a protection scheme
breaking a password. A password is a type of authentication key. Password crackers are
utilities that try to ‘guess’ passwords.

The word ‘Tempest’ is usually understood to stand for “Transient Electromagnetic Pulse
Emanation Standard”. Tempest is the ability to monitor electro-magnetic emissions from
computers in order to reconstruct the data. This allows remote monitoring of network
cables or remotely viewing monitors.

Password Trojans search the victim’s computer for passwords and then send them to the
attacker or the author of the Trojan.
Privileges-Elevating Trojans are the Trojans that are usually used to fool system administrators.

Key Loggers are the trojans are very simple. They log all of the victim’s keystrokes on the
keyboard (including passwords), and then either save them on a file or e-mail them to the
attacker.

The computer virus can also cause damage by destroying or altering data on a computer.
Basically, a virus is a computer program that is able to attach itself to other documents and
to move from computer to computer. Viruses are programs that attach themselves to a
computer or a file and then circulate themselves to other files and to other computers on
a network. They usually affect the data on a computer, either by altering or deleting it.

E-mail has become one of the world’s most preferred forms of communication.
E-mail spoofing is an effective medium to mislead people. A spoofed e-mail is an e-mail
that appears to originate from one source but has actually emerged from another source.

Denial of service attacks are usually launched to make a particular service unavailable to
someone who is authorized to use it. These attacks may be launched using one single
computer or many computers across the world. In the latter case, the attack is known as a
distributed denial of service attack. Usually, these attacks do not require the access into
anyone’s system.

11.4 Keywords

Macro: It is a series of commands to perform an application-specific task.
Packet Sniffing: It is a technology used by hackers to intercept and decrypt the data packets
flowing on a computer network.

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