The typical tech support scam presents itself to the user while browsing the web, in the form of a pop-up message saying that a virus or “suspicious activity” has been detected. A phone number is provided, of course, which the user can call to get “support” with this problem.
These pop-ups are usually the result of visiting a page that is either malicious itself, or that has been hacked, or that contains advertising from an ad feed that has been hacked. In any case, the page contains malicious code that either displays a pop-up, or redirects to a malicious page that then displays the pop-up (as shown in the image at right).
It is important to understand that no website can scan your computer for malware or suspicious activity. Further, Mac OS X will never display such a message within your web browser. (If you are unsure as to whether the alert is being shown by your browser or by the system, try hiding the browser by pressing command-H. If the message hides as well, it’s being displayed by the current page.) At most, web browsers can warn you that a particular site you are trying to visit is bad, but they cannot make any determinations as to the state of your computer.
It is also important to understand that these messages are not caused by a virus, or any other kind of malware. Many people’s first reaction to a pop-up like this is to go download anti-virus software. This is the wrong response, as there is no malware involved, and thus the anti-virus software will not solve the problem.
How to respond to the message
In short: don’t. Do not call the phone number provided, as it is not a real tech support number. The people at that number are scammers, and they will do their best to take advantage of you in whatever way you will let them. You just need to get rid of the message, which may be more difficult than it should be.
If you called the phone number, you may need to take some additional steps. For example, if you gave the scammers your credit card number when asked, you should contact your credit card company and report that your card has been compromised. If you gave other personal information that could be used to steal your identity
Read more on Adware Prevention: http://www.macgeek.la/adware/