855-291-6646

Just had a pop-up on my computer advising that I have been infected with a virus and that I should call them at this number 1-855-291-6646.  Said they were Microsoft Security.  Didn't call these fishers.  SCAM

agreed.  My mom called all freaked out.  You probably added an addware.  Google and follow directions to remove recent programs.

Computer was flashing a warning that a virus had been detected and to call that number. Person claimed to be Microsoft rep named Michael Smith. Claimed he scanned our computer and our IP address had been hatched. Quoted us several amounts ranging from $500 to $1400 to fix it. I ended the call to have someone else check it out.

Just got the same pop-up.  I have three anti-virus programs and none of them detected a problem. I know this wasn't a phone call, but the number still is dangerous.

Most pop ups are generated from a Browser Hijacker, located somewhere in the system files of your Browser. Many anti-virus programs don't detect them because they are part of the Browser's files and not considered a 'virus' by the programs, unless a specific file name is used and is in the definitions for the anti-virus app's search parameters.
You should use a more specialized program designed to search places these pop ups reside, such as malware removal and rootkit removal programs.

Here is a little info that might help clean them out for you.

https://malwaretips.com/blogs/remove-tech-support-scam-popups/
Norton Power Eraser:
https://support.norton.com/sp/en/us/home/curr ... erProfile_en_us
Malwarebytes Anti-Rootkit
https://www.malwarebytes.com/antirootkit/

Not quite correct. The browser pop-ups are embedded in the code in ads served up by ad servers used on many websites. In general, the website has no control over the ads themselves and the ad server companies are less than proactive in screening for these scareware/malware pop-ups.  Your web browser is simply executing the code supplied to it by the ad servers.  You can stop the majority of the scareware pop-ups by using an ad blocker add-on for your browser.  You can also stop them by using Task Manager to kill your browser in Windows or force quit the browser on an Apple device. You then clear your cache and browsing history and are fine until the next website you visit with a scam ad being served up.

I agree, it is one method to make a pop up appear to trick victims, but many people know to close the window/tab and it just goes away. Another method is a re-direct trick that takes you to a malicious website, even though you didn't click anything and attempts to hold you 'ransom' by making it very difficult to close the window/tab.

Most of those scam hackers utilize the analytical trackers on websites and need their code placed on your computer to better target you for a scam by looking at where you visit and when your browsing habit falls into the targeted range of the hijackers programmed instructions it launches the pop up.
The adware programs that generate illegitimate malware pop-ups and malware spam are capable of installing malicious code to hijack your browser. Most malware pop-ups and spam often appear because you already have malware on your machine. Those who create the malicious ads are more interested in hiding them on your computer to spread them while avoiding detection and gives them a higher probability of scamming someone because closing the browser and clearing the cache won't get rid of it. Soon enough, it pops up again.

For most people, it is just a website they visited with a harmless pop up, but for people who seem "prone" to getting the same one or same type, its a safe bet its due to a hijacker on their device. Some of the more sophisticated ones will self-update and those are the ones that are really well hidden and require a rootkit removal.