Backdoors are used to provide access to a system after the attacker has defeated the security mechanisms and gained control of the system. When the programmer writes the code for an application, he deliberately installs the backdoor. In some circumstances the programmer installs the backdoor for administrative purposes; however, attackers can detect these backdoors or install their own backdoor. A backdoor is a way of retaining the illegal entrance to the system for further exploiting the system. In addition, by using a backdoor, the compromised system can be used for launching denial of service attacks to other systems.

Logic bomb

A logic bomb (or slag code) is special programming code attached to other files that is triggered only after a predefined period of time has passed, on a specific date, or when a specific even occurs. For example, a virus can be considered a logic bomb if it is activated at a certain time. Logic bombs can be set to alter your file, format your hard drive or execute any other undesirable action.

Mobile code

The need for dynamic content has lead to the adoption of mobile code like Java Applets and Active X. Malicious code written in these languages can be executed when executing the associated Web page; their target is usually to steal data or disable the systems.

Conclusions

In this article I listed the threats associated with malicious code and specifically I’ve talked about six threats that are under the malicious code umbrella. As I said in the introduction of this article the list of threats is endless; more threats will be discussed on the next part of this article.