Just checked it and it seems suspicious. There is no mention of this extension on Avira's website, there are only 3000 users, 5 reviews and it's fairly new (september 2017). It also has a very short description unlike other Avira's extension. Searching Google with the direct link to this extension brings up... 3 results. So i would not install this extension and consider it suspicious until proven otherwise. You could eventually contact Avira and send them the link if your really want a definitive answer.

For the record, Avira has an extension protecting your browser. It was called Avira Browser Safety but it recently changed to Avira Safe Shopping (the link to Avira Browser Safety now redirects to the new extension). So i would highly suggest installing this extension instead as it's the official from Avira. The change of name indicates that the focus is now more on "shopping protection" than anything else. And by that, read "we will redirect you to sponsored stores to make money", a practice i dislike in security companies. But if it's web blocking is still as good as before, it's definitely worth a try.

Avast Online Safety and McAfee SECURE are two other good alternatives.

As a rule, i would suggest to download extensions directly from the official website or by making sure it is the real deal (in the store since a long time, lots of users, positive reviews, etc...).