Malware
Malware (a portmanteau for malicious software) is any software intentionally designed to cause damage to a computer, server, client, or computer network. Malware does the damage after it is implanted or introduced in some way into a target's computer and can take the form of executable code, scripts, active content, and other software. The code is described as computer viruses, worms, Trojan horses, ransomware, spyware, adware, and scareware, among other terms. Malware has a malicious intent, acting against the interest of the computer user—and so does not include software that causes unintentional harm due to some deficiency, which is typically described as a software bug.
Web threat
In August 2008, popular social networking sites were hit by a worm using social engineering techniques to get users to install a piece of malware. The worm installs comments on the sites with links to a fake site. If users follow the link, they are told they need to update their Flash Player. The installer then installs malware rather than the Flash Player. The malware then downloads a rogue anti-spyware application, AntiSpy Spider.