I’m always hesitant to install Flash in my browser, I had to today to view some bike content on a Swedish site but it came with the price of adware. Surfbuyer to be exact.
If you ever come across Surfbuyer adware on your Mac affecting your Chrome browser or equivalent. You can do searches by most recent date in your Applications Folder and remove suspicious applications there.
In my case those were the files in the screenshot below, notable Optibuy and I also removed CoreUpdates and who knows how MegaBackup got there as well – bundled Flash software. I tried using MacKeeper to remove the malicious software but just went the manual route. Also search for recent installed files in your Library Folder. Within the Library folder (you get to the Library folder by Go -> Go to Folder in Finder) search in the Applications Support, LaunchAgents and LaunchDaemons for recent installed files and move those to the trash that may be suspicious. Good luck
Also don’t forget to look at recent installed Chrome extensions.