Malicious Code: Meaning and Its type

Meaning:-

Malicious code is any program that causes undesirable effects on an information system. Examples of malicious code include computer viruses, network worms, trojan horses, logic bombs, spyware, adware and backdoor programs. As they pose a serious threat to software and information processing facilities, precautions must be taken to prevent and detect malicious code.

(a) Malicious code is a new kind of threat which cannot be blocked by anti-virus software alone. In contrast to viruses requiring a user to execute a program in order to cause damage, malicious code is an auto-executable application. It can take the form of Java Applets, ActiveX controls, plug-ins, pushed content, scripting languages, or a number of new programming languages designed to enhance Web pages and email.   

(b) Malicious code is a code causing damage to a computer or system. It is a code not easily or solely controlled through the use of anti-virus tools.

Malicious code can either activate itself or be like a virus requiring a user to perform an action, such as clicking on something or opening an email attachment.

(c) Malicious code does not just affect one computer. It can also get into networks and spread. It can also send messages through email and steal information or cause even more damage by deleting files.

Types of Malicious Code

They are of the following types:-

1)    Access Violations:-

The most dangerous malicious code is that which tries to access (delete, steal, alter, or execute) unauthorized files. The attacks can steal passwords, files, or other confidential data. Some examples of company information that may be exposed include login names and passwords, secret project information, IPO plans, credit card numbers, confidential phone numbers, social security numbers, addresses, and much more. Code can also delete, encrypt, or modify files on disk. Access violation attacks require behaviour monitoring and can't be effectively blocked by 'code scanning' methods.

2)    Denial of Service Attacks:-

Denial of Service attacks prevent the user from using the system, and may destroy files that are open at the time of the attack. They work by performing repetitive tasks like opening an infinite number of windows until the system locks up. These types of attacks can be stopped through inspection of all incoming content.

Courtesy:- Legal Point Foundation