There are various different kinds of the malicious threats to the computer that remembering each of them is bit tedious. The threats include virus, malware, adware, Trojans but apart from these there is Scareware about which not everyone is aware of.
Scareware is a type of software that frightens you into downloading and purchasing certain rogue products (for e.g. fake antivirus, fake firewall). Scareware frightens you into installing the rogue product by displaying screens of your computer being attacked and claiming to be the solution to that attack. Typically, they are the result of scripts stitched into legitimate, hacked web sites, or into banner ads.
If you fall into the prey of this Scareware attack and if it gets installed in the system then it can invade your computer and attempt to record your keystrokes and banking/personal information. It can also attempt to take remote control of your machine to serve as a spam-sending Zombie robot.
The safest way to avoid being a victim to scareware is to:
1. Not click on any of the buttons within the browser window and instead, close the entire browser screen.
2. Run an antivirus scan immediately to ensure that new viruses have not been installed by the software.