U.S. credit reporting giant Equifax announced Thursday that a cybersecurity incident could potentially impact approximately 143 million U.S. consumers.

Equifax said in a statement that criminals managed to gain access to certain files, including consumers' names, Social Security numbers, birth dates, addresses and, in some instances, driver's license numbers.

The unauthorized access, which was discovered on July 29, occurred from mid-May through July 2017, according to Equifax.

The company added that credit card numbers for approximately 209,000 U.S. consumers were obtained.

Equifax said it will send direct mail notices to consumers whose credit card numbers or dispute documents with personal identifying information were impacted, and that it is in the process of contacting U.S. state and federal regulators.

Shares of Equifax slumped over seven percent on Thursday.