This is new kind of virus that is getting a lot of air on the Internet. If your computer prompts about something related to “security tool” and tell you to delete files or do something for Malware removal then don’t do anything. This security tool is the Malware itself and it must have landed on your computer because you downloaded it somehow. You should start working on removing this Malware right now.
Update your anti-virus and install one if you don’t have already. Next, install and update a spyware and Malware removal tool. There are some very good ones available at cnet, which can remove this security tool Malware too. And remember, this particular security tool Malware runs a diagnostic and tell you to upgrade to full version before you can remove the viruses, don’t fall for it. you will pay and lose the money, and moreover you might even leak your payment details.
Remember, this particular virus, named as the security tool will act as a genuine anti virus program and it will install itself in your computer. Next it will do a scan and show you a list of fake infections, so do not delete those files it shows as infected. If you do so, then you might lose some important files. After that it will ask to upgrade to the full version, do not do that.