HTML:Dropbox-B [Phish] Repeated Alerts

Hi Don,

We will certainly check this for you.

Please provide us the screenshot of the threat pop up to check and assist you further.

Product: Avg Free on Windows 10 (both fully updated):
Ever since the middle of October 2018 I am repeatedly seeing the following message pop up:
"We've safely aborted connection on secure-ds.serving-sys.com because it was infected with HTML:Dropbox-B [Phish] Threat Alert."  This happens multiple time a day, and I am not on any dodgy websites. I have scanned my entire computer with AVG and also Malwarebytes with no results.  It appears to be a false positive for an ad server. Any thoughts on what is happening here?

Hi Don,

We will certainly check this for you.

Please provide us the screenshot of the threat pop up to check and assist you further.

ss