Does anyone know if avast free or full purchased version have AntiDrive-by download protection ? And also does the free version automatically stop malicious code from executing on a pc environment? If you dont know what these are, you could google them. I was just wondering if avast free and full Ver. includes these protections.
Yes, avast detection caught these kind of infections.
Of course, neither a detection software is perfect and you need to add safe browsing to your habits.
Whilst the web shield is very good at detecting these hacked sites with the injected script tags, iframes, etc.
If you are using Firefox, then you should be using the NoScript add-on as driveby downloads need to be run, generally through a hacked site, iframe or script tags, redirect, etc. by default NoScript blocks all scripts unless you specifically allow scripts on that page. So it pays to have protection in depth and the NoScript add-on adds another level.
You could go a step further and include the RequestPolicy (RP) add-in, which blocks cross site scripting, often these scripts aren’t actually on the page that you are visiting, but on another site with a call to run the script.
The RP add-on combats that cross site scripting unless you give permission, but some find this a bit too intrusive as some sites may have many cross site scripts
As the OP is asking about both Avast! free and paid, it should be mentioned that the paid verslons of Avast! have a Sandbox you can virtualise your browser(s) with. So if a drive-by download is not detected by Avast!, it will be isolated in the Sandbox and can not harm your real system 
Greetz, Red.