I would recommend Avira as free internet security solution. Web-shield is provided by avira browser safety extension, if you are using avira free. In Avira there is no kind of behavioural blocked (some heuristics though, called APC). There is no real need of any behavioural blocker, considering all new suspicious executables are uploaded to the cloud for an instant analysis.
The problem comes if avira doesn't recognise a new file as suspicious (it won't upload it), or if protection cloud is unable to recognise malicious code in the sample uploaded (rare though).
Avira is really good at default settings, no need to tweak it. Avast is a good product and have more user friendly features, but you have to enable PUP detection, which is disabled by default and hardened mode (can cause some false positives) for better protection.
Though there are many other http://https://www.criticthoughts.com/security/free-and-paid-antivirus-comparison/" rel="nofollow - best free antivirus solutions available, it depends according to your need that which one will suit you more may be you need paid at times as I also use the Paid version of http://https://www.criticthoughts.com/security/bitdefender-total-security-review/" rel="nofollow - Bitdefender total security which is a fully integrated system.
I set it up and set to "Autopilot" and rarely hear from it, or even know it's running, except for a weekly report and a few Anti-ransomware alerts, any new program will be prevented from writing to, or modifying, any "protected" areas, until I review and allow it
As a complete system it is unlimited devices and works with Windows, MacOS, Android, and iOS devices so provides a multi-point defence against threats getting onto my systems