Malware: Fighting Malicious Code

Summary

A virus is self-replicating software that spreads by attaching itself to other programs. In most cases, a human is expected to take action, such as opening the infected program, to activate the virus. Once activated, the virus can continue propagating by attaching to other programs accessible to the victim. Activating a virus might also trigger its payload, which is typically programmed to perform destructive or distractive actions such as deleting files, corrupting data, or displaying messages on the victim's screen.

A virus can attach itself to several types of carrier programs: executable files, boot sectors, documents, scripts, and so on. Specimens that target executables or scripts typically infect their hosts via overwriting, prepending, ...