avastPetr Chocholous in response to Iranian users contacting avast saying they are unable to open website or update their antivirus said:

AVAST Software a.s. is currently blocking access to port 80 (that effectively means websites and updates of avast! software) of its servers from following countries: Iran, Sudan, Cuba, Syria, North Korea and Burma/Myanmar. AVAST Software a.s. [and its subsidiaries/sister companies] must not provide any services in these countries because of policies and regulations that are applicable to AVAST Software a.s.

Blog and forum are available, because we hope they are information source/personal communication service and because of this they have exclusion from these regulations.

We are sorry for any caused inconvenience.