Malware Information

What is Malware?

Malware (mal´wãr), short for malicious software, is designed specifically to damage or disrupt a system. The term describes the intent of the creator, rather than any particular features. Malware is commonly taken to include computer viruses, Trojan horses, and Spyware.

Viruses are self-replicating programs that spread by inserting copies of themselves into other executable code or documents. A computer virus behaves in a way similar to a biological virus, which spreads by inserting itself into living cells. Extending the analogy, the insertion of a virus into the program is termed as an infection, and the infected file is called a host. Many DOS viruses were designed to destroy files on a hard disk, or to corrupt the file system by writing junk data. Since the rise of widespread broadband Internet access, the greater portion of malicious software has been focused strictly on a profit motive.

Spyware is designed to intercept or take partial control of a computer's operation without the informed consent of the user. While the term taken literally suggests software that surreptitiously monitors the user, it has come to refer more broadly to software that subverts the computer's operation for the benefit of a third party. Typical tactics furthering this goal include delivery of unsolicited pop-up advertisements; theft of personal information or monitoring of Web-browsing activity for marketing purposes. As of 2005, spyware has become one of the pre-eminent security threats to computer-systems.

Trojans are any program that invites the user to run it, but conceals a harmful or malicious payload. The payload can lead to many undesirable effects, such as deleting all the user's files, or more commonly it may install further harmful software into the user's system to serve the creator's longer-term goals.

Worms are self-replicating computer programs, similar to a virus. A virus attaches itself to, and becomes part of, another executable program; however, a worm is self-contained and does not need to be part of another program to propagate itself.