Why do not I have access to the site with IP?
Why have you blocked Iran?
By “you” you mean Avast? As in Avast has blocked Iranian IP?
We evangelists are users just like you and are not a part of the avast team. We volunteer our time in order to help other users with any issues they may have with avast and related products.
So why the block?
Well, one possible reason is because they are required to, as a corporate citizen in the world and international community.
Bombastic!
Who’s bombastic? You? Or Avast? Can’t be yours truly as I’ve nothing to do with the way things are.
Besides, not fully including the entire quote is twisting words and intent:
Access Denied
You don’t have permission to access “http://www.avast.com/” on this server.
Reference #18.9fd91002.1528225116.2d502c1
and isnstall avast internet security.
not running and message not available in your country.
Avast is not only a EU based firm, but also a USA based company,
so avast has to live up to Us regulations, no two ways about this.
You can check what is blocked in Iran: https://www.comparitech.com/privacy-security-tools/blockediniran/
In the old days you could get the code and updates from a CD inside a computer magazine 
so also a good idea when there is no direct Internet connection anymore.
Also consider this list: https://www.comparitech.com/blog/vpn-privacy/best-vpn-for-iran/
I hope you will see better days without mutual technology (export) bans, but it always needs two to tango
polonus