Fake alerts and warning pop-ups always precede rogue infections. In some cases, the rogue installation is triggered by clicking on such an alert. Therefor, it is recommended to take precautions before the phony anti-virus program has managed to enter the computer.
"System Warning" pop up is one of the alerts that are caused by Trojans, which have managed to sneak into a vulnerable computer system. The warning states:
System warning: Intercepting programs that may compromise your privacy and harm your system have been detected on your PC. Click here to remove them immediately with the latest version of System Protector
As you can guess by the text above, the pop up advertises a rogue anti-spyware – System Protector. In reality, there are no "intercepting programs" – this pop up only aims at advertising the rogue by using deceitful information.
Clicking on the alert will automatically download and install the villain on the computer. On its own, the warning is not very harmful, it can connect to the Internet and show adverts regarding System Protector. If it catches you off guard, however, and you unvoluntarily click on it, the rogue download can cause serious system damages and security problems. System Protector is capable of:
These tactics are all used with the only intention of scaring the victim into purchasing the full version of the rogue, which is as useless as the trial one.
To keep fake AVs away from your system, you should be very careful when noticing such alerts on your computer. In such cases, it is highly advisable that you run a scan of the PC with your legitimate AV software after the first time you spot the alert so that the Trojans causing it can be removed before the rogue has managed to sneak into the computer.