Session 13

Session 13
Date:11.3.2010

Activities:
- Discussed about malicious codes

Malicious code is also known as a rogue program. It is a threat to computing assets by causing undesired effects in the programmer’s part. The effect is caused by an agent, with the intention to cause damage.The agent for malicious code is the writer of the code, or any person who causes its distribution. There are various kinds of malicious code. They include virus, Trojan horse, logic door, trapdoor and backdoor, worm and many others.
a) Virus
- A program that can pass on the malicious code to other programs by modifying them.
- Attaches itself to the program, usually files with .doc, .xls and .exe extensions.
- Destroys or co-exists with the program.
- Can overtake the entire computing system and spread to other systems.

b) Trojan Horse
- A program which can perform useful and unexpected action .
- Must be installed by users or intruders before it can affect the system’s assets.
- An example of a Trojan horse is the login script that requests for users’ login ID and password.
- The information is then used for malicious purposes.

c) Logic Bomb
- Logic bomb is a malicious code that goes off when a specific condition occurs.
- An example of a logic bomb is the time bomb.
- It goes off and causes threats at a specified time or date.

e) Trapdoor and Backdoor
- A feature in a program that allows someone to access the program with special privileges.

f) Worm
- A program that copies and spreads itself through a network.