Credit monitoring company Equifax was the victim of an unprecedented hack on its systems.

The breach exposed social security numbers and other data from millions of Americans, as well as some Canadians.

The Atlanta-based company says that “criminals” exploited a U.S. website application to access files between mid-May and July of this year.

These files include names, social security numbers, birth dates, addresses, and driver’s license numbers—all of which could be used toward identity theft.

According to investigation, 140 million consumers were exposed and more than 200 thousand U.S. credit card numbers were accessed.

The company says limited information from British and Canadian residents was accessed. No other countries are believed to have been affected.