It looks like that's coming from some type of over-zealous security software. This has nothing to do with ads - Google Analytics collects site statistics with a small bit of Javascript at the bottom of the page. Your security software doesn't like the fact that the security certificate registration for that bit of code is with google.com, rather than google-analytics.com (which is where the javascript is actually hosted). The only thing you can do, really, is to adjust your security settings or notification options.