Not to worry! Pornhub.org is an official Pornhub domain.
Is it safe to enter my credentials on pornhub.org?
Absolutely, it is safe to log in through www.pornhub.org. Depending on your Country, it will redirect you to Pornhub.com.
What are other domains that are offered by Pornhub?
Pornhub.org
You-porn.com
Redtube.net