So, I had a couple people from my cyber security team run some tests. They found the pop-ups are often triggered by keywords in the website itself. The "BSOD Error 333 Registry Failure" pop-up, “CLUSTER ERRORS DETECTED ERROR 777" pop-up, or any number of similar pop-ups might offer a social engineering scam such as a Flash Player update, a Browser Update or redirect you to a bogus telephone support scam to "fix your computer." As the pop-ups are so random it’s hard to say which pop-up might occur on your computer; as stated above these pop-ups are based on keywords found in the content of the website. Clicking on different word links will pop-up different scams, some of which are far more serious than others.
If you clicked on the "X" box to close or clicked on "OK", there's a generally accepted procedure to rid your system or device of any related viruses, malware, spyware or other exploits:
OPTIONAL – Close the pop-up
Step 1 – Remove pop-up using AdwCleaner
Step 2 – Remove files with MalwareBytes Anti-Malware
Step 3 – Remove from your browser with Avast Browser Cleanup
Step 4 – Optional step: Reset browser settings
(If you experience any of the pop-ups on Mac OSX from Apple, follow this generic guide to remove adware from Apple Mac OSX: https://www.fixyourbrowser.com/how-to/remove-adware-mac-osx-safari-chrome-firefox/
(for the Safari, Google Chrome and Mozilla Firefox browsers in Mac OSX)
Here's a link to the information at FixYourBrowser.com for MS Windows systems. It doesn't matter which scam you're encountering, the repair instructions are pretty much the same for all of them. The site includes secure download links to all the cleaners they talk about, and there are free versions of each of them that are fully functional. Just follow the instructions and it's pretty simple. https://www.fixyourbrowser.com/removal-instructions/remove-cluster-errors-detected-error-777-pop-up-tech-support-scam/
If it's more serious and other things don't work, there are a lot of free resources to help you.
- Free Virus Removal Tools at SOPHOS.com: https://www.sophos.com/en-us/products/free-tools.aspx
- McAfee is committed to security and provides an assortment of free McAfee tools to help, including rootkit scanners: http://www.mcafee.com/us/downloads/free-tools/index.aspx
- SUPERAntiSpyware Free Edition is 100% Free and will detect and remove thousands of Spyware, Adware, Malware, Trojans, KeyLoggers, Dialers, Hi-Jackers, and Worms. SUPERAntiSpyware features many unique and powerful technologies and removes spyware threats that other applications fail to remove. Here's the link: http://www.superantispyware.com/superantispyware.html
You should be fine! Just don't call them or give any credit card or other financial data to ANYONE related to these scams!