Personal information of 143 million people may be compromised after a cyber breach in a major credit reporting agency.

As some people checked to see if their information had been compromised through Equifax's security site, the information of minors appeared.

RELATED: 143 million people could be affected by Equifax cyber breach

One viewer wrote to 9NEWS,

"Even my 8 and 10 year old boys come up as potentially they really have information on minors?"

Personal data that may have been compromised by cyber criminals includes names, social security numbers, birth dates, addresses, and even some driver's license numbers.

"Anybody could be affected just because social security numbers are given to every person who's a U.S. citizen," Tijuan Harvey said. Harvey is vice president of the Young Americans center for financial education. It's the only bank for young people 21 and under.

Harvey said it is not unusual for minors' information to be used for credit purposes.

"It could be a family member who ran across a young person's social security number," Harvey said, alluding to the idea that a family member might use a child's social security number, for example, to obtain a credit card.

Equifax said it has alerted law enforcement, the U.S. attorney general, and state attorneys general about the breach.

For more information on how to check to see if you have been affected, click here: