I made the mistake a few days ago of installing the flash update. Turned out to be a virus that took over my three browsers, Safari, Firefox and Chrome. What the virus does is it redirects your browser startup page to searchmine.com. It also locks your browser startup page preferences so that you can't change it.
After researching for a while I found that this virus only affects the browsers, but is a major pain to remove from your system. Basically, it installs a few false apps into your applications folder. Then it creates a folder in your HD/Library/Managed Preferences. That folder is what is controlling the browsers. But you can't just delete it. It comes back after a restart. I found a blog that has a list of items to remove from your system, but you do have to have a certain level of confidence in doing this yourself.
This the blog that helped me most.
(
https://malwaretips.com/blogs/remove-searchmine-net/).
What worked for me was removing three apps from my applications folder that I know I did not install. They were not the ones listed in the blog, but they were definitely not mine. I deleted everything inside the HD/Library/Managed Preferences. Lastly, I opened System Preferences and I found a "Profiles" icon that didn't belong and deleted it.
This is what worked for me, but there are more intensive instructions on the blog. This all happened on my Mac Desktop and now it's clean. But the CNN website thing is happening on my LapTop now. I have no idea how to make that stop, but I won't be making the same mistake twice. I hope this helps anyone who has made the same mistake I made. Also, once the virus was in my system, neither Malwarebytes nor Sophos detected anything wrong and so were useless in removing it. This is why I did it manually.