TL:DR
Hackers compromised 143,000,000 Americans (and some foreign) accounts at Equifax with important personal info like SSN, address, etc... You have to dig through a few links on their statement page to find the page where you can check if your accounts might have been compromised (and if so, get free credit monitoring - they give you a "call back" date for registering with no reminders, how nice of them)
Here is the page where you can start the process to see if you were compromised (you can verify the link below from Equifax homepage):
https://www.equifaxsecurity2017.com/potential-impact/
Read More:
https://gizmodo.com/hackers-steal-personal-information-of-143-million-ameri-1802136954
Equifax statement: https://www.equifaxsecurity2017.com
You can find a link to the statement and the potential impact page via the Equifax homepage to verify them if you want: https://www.equifax.com/personal/