Hi Mike,
Never seen a Chrome-specific scareware before. Interesting. I can tell you that from 2012-2014 I wasn't running Firefox, as they were having a spate of similar scareware, Trojan-virus infections and other weird computer-killing type actions, back around v24.0 and v41.0 or something. I had several of my seniors in my local Computer Club have their PCs and laptops killed by Firefox; so we banned it from use by recommending that practice in our meetings, workshops, and via E-mail blasts to our Club membership. Only recently starting using Firefox again in 2015 a bit, and more in 2016 and they've seemed to weed out most of the bad nasties from Firefox; it's a GNU-license public domain that Mozilla uses for the Firefox browser engine, so they are dependent on a volunteer-community internationally populated to doing the "weed-pulling" as many of us malware guys call it from their products, so it takes them years to get a stable, virus-free program. If you read the fine print in the Mozilla-Firefox EULA, they never guarantee that Firefox is virus-free, but their lawyers very clearly state that your acceptance of the EULA, by your installation of the program provides them with a financial hold-harmless statement that frees them from any liabilities they might have if their program passes along a virus that wipes out your stuff or causes you to have to pay money for repairs, unlock Ransomware, etc. etc. This language has gotten stronger and stronger, and the last time I read it, it seems that they are really gun-shy about getting sued by Firefox users who incurred virus-related damage during their 3 year apocalyptic stint where knowledgeable users refused to run it. I myself, removed it on over 100 computers since it was wreaking such havoc. So, it's possible, not likely FF is at fault, but I certainly don't rule it out.
I can tell you that since the 2012-2014 FF debacle, I never, ever run FF on my production machines;
"daily-drivers"! I only run FF on my W10 test machines, and on customer machines where they insist that's their favorite browser and refuse to use anything else. After having them sign a hold-harmless waiver, I put FF back if I removed it during diagnosis or repair, and walk away.
Another interesting side-note is that when FF first came out, the College I was teaching at back in about 2006 paid to have a study done on which browsers should be used in classrooms and computer labs on and off campus. Study came back that FF had an unusually large number of security holes inherent in it's design and it should not be used for access to online student portals such as the Blackboard classroom curriculum and testing management program used around the country in Colleges and Unis.
My College then stated in no uncertain terms the only
"officially sanctioned" browsers were to be IE6 or higher and Chrome. No other browsers were supportable.
Additionally, further research with academic program vendors such as Blackboard and Moodle, also refused to allow use of FF with their programs.
We didn't find that out until months after the study was done and the new portal access policies were put into place however. I've heard similar stories from many of my teacher colleagues who taught at other public and private colleges and k12 schools the last few years.
Food for thought.
BBJ