Please don't assume that just because your computer is working fine now that you didn't "get infected." A "bad" computer virus (meaning the bad guys did their job wrong) makes your computer really slow and otherwise forces you to notice it. If that happens you usually do something to remove the virus and it's out of business. It doesn't stay on your computer long enough to do the damage they want it to.
A really good computer virus/malware/hacker will run in the background without you even noticing. There may be some clues but especially if you aren't tech savvy you will probably blame yourself. You may think you set a different home page in your browser, or you need a restart because things seem a little slow, you see something flash on your screen before you can read it but then think it was just in your head, etc. Danger Will Robinson! You may be infected!
As previously noted, never click on the popups. You shouldn't even click the "X" in the upper right corner to close it. If you can, right-click the icon at the bottom of your screen and select the "Close" option. That's the safest way I know to close a window with a popup.
I'm sure others here have good ideas and I'm hoping to read them. I think I will post my own thread about a Chrome issue if you want to read and share on that one too.

KJPA