Google Chrome rampant "Infection blocked!" popups [problem solved]

I’ve been using Avast for almost a year and it’s been working great. Today, all of a sudden, every time I load a page in Chrome (and often multiple times on the same page) the attached bubble pops up. It does NOT happen in Safari.

It reads:

Infection blocked!
Avast Filesystem shield has blocked a threat.
Infection: HTML: lframe-inf
User: ameliajensen
Process: /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
File: /Users/ameliajensen/Library/Caches/Google/Chrome/Default/Cache/data_1

I can’t think of anything weird I did or any unusual sites I visited that might have started this problem, and I can’t find the file it’s referring to. Since it says it’s being blocked, I assume my computer is safe, but I can’t figure out how to make it stop. Any idea why this is happening?

I’m running a full system scan right now to see if I can turn anything up.

Thanks for your help.

Full system scan identified file, was able to delete. Case closed. Sorry y’all.