You probably heard Equifax was breached -more info here: https://krebsonsecurity.com/2017/09/the-equifax-breach-what-you-should-know/
Go here and enroll: https://www.equifaxsecurity2017.com/enroll/
Once you’ve enrolled (and Equifax has confirmed you’ve enrolled), follow the instructions here to put a freeze with all 4 credit bureaus:
Equifax, Experian, Innovis and Trans Union
You also should probably put a freeze on your child’s credit while you’re at it.