Malicious Code

• Software programs having malicious intent which are designed to infiltrate and damage computers without the users are known as Malware or malicious code.
• The types of malicious code are:

i. Virus:

This is a malware that relies on someone or something else to propagate from one system to another. It distributes its own copies to other non malicious programs by modifying them.

Example: An email virus attaches itself to an email that is sent from one user to another.

ii. Worm:

This is like a virus except that it propagates by itself without the need for outside assistance using a network to spread its infection.

Example: Code Red worm may crash the Operating system and other devices connected under the same network.

iii. Trojan Horse:

Trojan, is software that appears to be one thing but has some unexpected functionality. It does not replicate itself.

Example: An innocent-looking game could do something malicious while the victim is playing.

iv. Trapdoor:

This is also called as backdoor which allows unauthorized access to a system. Trapdoor is like a fault in the system through which an attack is possible.

v. Rabbit:

This is a malicious program that exhausts system resources. Rabbits could be implemented by replicating itself without limit using viruses, worms, or other means. It can block resources and networks.

vi. Spyware:

It is a type of malware that monitors keystrokes, steals data or files.