Here’s how to find out if your Social Security number was included in last week’s massive data breach

Last week’s stunning data breach at National Public Data put the personal data, including Social Security numbers, of billions of Americans in the hands of cybercriminals.

The breach occurred late last year, and the company acknowledged on its website last week that there were “potential leaks of certain data in April 2024 and summer 2024.”

Data dating back at least three decades is said to be included in the breach — and the inclusion of Social Security numbers has raised a number of concerns among people. Curious if you’ve been affected? Here’s how to find out.

How can I find out if my social security number was part of the breach?

Pentester, a cybersecurity firm, has created a tool to let you see if your data was part of the breach. Use a web browser to navigate to npd.pentester.com and enter your first and last name and year of birth. You’ll see a list of compromised accounts, including the last four digits of the leaked social security numbers.

What should I do if my social security number was included in the breach?

NDP advises people who may have been affected to closely monitor their financial accounts. Most Americans don’t keep a close eye on their checking and savings balances or examine every item on their credit card bills — and hackers count on that.

It’s also a good idea to set up credit monitoring to make sure no one is using your personal information and to contact one of the three US credit reporting agencies (Equifax, Experian and TransUnion) to set up a fraud alert on your account that you tell creditors to contact you before opening new accounts or changing your existing accounts. Once established with one agency, it will take effect with the others. It remains active for one year and can be renewed.

If you’re particularly concerned about identity theft, there’s another option: a credit freeze, which prevents new credit from being issued without your direct permission.

“The best protection against someone opening new credit accounts in your name is a security freeze (also known as a credit freeze), not the oft-offered and ineffective credit monitoring,” notes the Public Interest Research Group from the USA.

This story was originally featured on Fortune.com