Sunday, February 28, 2010

Security Threats

Malicious code

  1. Malicious code is also known as a rouge 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 distributions. There are various kinds of malicious code. They include :

a. Virus
b. Trojan Horse
c. Logic Bomb
d. Trapdoor / Backdoor
e. Worm

o virus

§ Virus is a program that can pass on the malicious code to other non-infected programs by modifying them.

§ To infect a computer, the virus needs to attaches itself to the program, usually files with .doc (document), .xls (spread sheet), .exe (executable file) extensions.

§ It will then destroy or co-exists with the program.

§ Once the infected file is open, the virus will copy itself into that particular system and perform its functions.

§ Eventually, it can overtake the entire computing system and spread to other connected systems.


o Trojan Horse

§ A program which can perform useful but unexpected actions.

§ 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 request for users’ login ID and password.

§ The user will then successfully pass the login process, but the Trojan horse will keep a copy of the information to be use for malicious purposes.


o 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.


o Trapdoor or backdoor

§ A feature in a program that

allows someone to access the program and use it with special privileges.


o Worm

§ A program that copies and spreads itself through a network.

§ Primary differences between worms and viruses.



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