Remove the Your device is under threat Tech Support Scam

The Your device is under threat Alert is a web browser based tech support scam that tries to trick you into calling a remote support number. This alert display an alert that pretends to be Windows defender security states that your device is under threat. It then prompt you to call a remote support number. As this is a scam, you should not call the listed phone number as they will just try to sell you unnecessary services and software.

When the Your device is under threat Alert is displayed in your browser it will display an alert that contains text similar to the following message:

Windows defender security center
Your device is under threat.
Last threat scan: 11/10/2017
Last threat definition update: 11/10/2017
Last threat scan: 11/10/2017
Turn on Real-time protection? Yes/No
Virus & Threat Protection
Real-time protection is off.
Leaving your device vulnerable
Device performance & health
No action needed
Firewall & network Protection
No action needed
Turn On

Once again, this is just a fake alert and the page does not know if your computer has an error or a virus, does not know what is running on your computer, and is just trying to trick you into calling the phone number. At this same time, for those who have never seen a message like this, they can be quite alarming as these scams make it difficult to close browser tabs or the browser itself.
Thankfully, almost all browser based tech support scams can be closed by simply opening Windows Task Manager and ending the browser process. It is important, though, that if you end the browser process that you do not reopen previously closed sites if prompted by the browser when you start it again.
On the other hand, if you are constantly seeing these types of tech support scams, or these pages are opening by themselves, then it may be possible that you are infected with an adware or other unwanted program that are displaying them. Once again, do not worry as it is quite easy to remove these infections if you follow the guide below.

Why am I Seeing the Your device is under threat Alert?

The Your device is under threat Alert is shown through advertisements that redirect you to sites that display this scam. These advertisements can be displayed by installed adware programs or through less than reputable sites that are displaying them to generate advertising revenue.
For the most part, if you see a browser based tech support scam, then you can simply close the browser and start it again. On the other hand, if you are continuously seeing scams with alerts like "Your device is under threat", then you should scan your computer for adware and remove anything that is found.