CHICAGO — Illinois Attorney General Lisa Madigan is urging residents to take precautions after credit-monitoring company Equifax said a breach exposed information about 143 million Americans.

Madigan said Friday that she has started an investigation in the breach and called on Equifax to provide free credit freezes to all Illinois residents. She says potential risks for consumers are serious and urged Illinoisans to take precautions, like freezing their credit, to reduce any damage.

Atlanta-based Equifax on Thursday said a U.S. website application was exploited to access files between May and July of this year. The theft obtained consumers’ names, Social Security numbers, birth dates, addresses and, in some cases, driver’s license numbers.

The company established a website, https://www.equifaxsecurity2017.com/ , where people can check to see if their personal information may have been stolen.