Scareware is malicious software that tricks computer users into visiting malware-infested websites. Also known as deception software, rogue scanner software or fraudware, scareware may come in the form of pop-ups. These appear as legitimate warnings from antivirus software companies, and they claim your computer's files have been infected. They are so cleverly done that users are frightened into paying a fee to quickly purchase software that will fix the so-called problem. What they end up downloading, however, is fake antivirus software that is actually malware intended to steal the victim's personal data.

Fraudsters also use other tactics, such as sending out spam mail to distribute scareware. Once that email is opened, victims are then fooled into buying worthless services. According to Kaspersky Lab, falling for these scams and releasing your credit card information opens up the door for future identity theft crimes.

Aggressive Scams

Reputable antivirus vendors don't solicit such data through scare tactics. But cybercriminals are well aware that many people don't know that. The FBI and various international law enforcement organizations continue to investigate these extremely aggressive criminal rings. One international cybercrime case investigated by the U.S. Department of Justice, for example, involved a crime ring that allegedly stole $71 million through software schemes.

Scareware follows a common pattern. Pop-ups suddenly warn you that dangerous files or porn have been found on your computer and will continue to pop up until you click on buttons that ""remove all threats"" or you are asked to register for antivirus software. If the antivirus message isn't from a program you had installed — don't click on anything. It's best to turn off the machine. Antivirus software can also scan for these sophisticated threats.