It would have nothing to do with the change/upgrade of program as essentially the scanning engines and signatures are the same.
Can you attach a screenshot of just the avast alert window or give the full details of the alert, full path/url and malware name and an example of the site you were visiting when this occurred ?
If posting the url, change the http to hXXp to prevent the link being active.
Personally I don't allow google-analytics (NoScript add-on, it can also be blocked using AdBlockPlus)) and the spelling in your Subject isn't correct for google-analytics, so I'm hoping it is a typo as there are many such instances of different spelling to confuse the user.
This is a commonly used urn for it hXXp://www.google-analytics.com/ga.js running a javascript file in pages you may visit. I believe there have been instances of the legit google-analytics being hijacked, so we do need more information.
EDIT - Note: actually blocking google-analytics can cause some sites not to work completely, but for the most part it doesn't effect them.