The NY Attorney General has launched a formal investigation into the breach of major credit reporting agency Equifax, which gave hackers access to millions of Americans' personal data. AG Eric Schneiderman says over 8 million New Yorkers may have been affected by the breach, which lasted from mid-May through July.

"The Equifax breach has potentially exposed sensitive personal information of nearly everyone with a credit report, and my office intends to get to the bottom of how and why this massive hack occurred,” Schneiderman said in a statement today. “I encourage all New Yorkers to immediately call Equifax to see if their data was compromised and to consider additional measures to protect themselves."

Equifax revealed the breach to the public on Thursday, noting hackers were able to access Social Security numbers, birth dates, addresses, credit card numbers and even driver's license numbers. 143 million Americans were affected in the breach.

Schneiderman's investigation seeks to find out whether customers were properly notified of the breach, and whether or not customers were appropriately protected. According to state law, businesses with customers in New York have to inform both customers and the AG's office about these kinds of data-revealing breaches. The AG says he's sent a letter to Equifax to find out more.

Equifax's shares fell 13 percent following the breach announcement. CNNMoney reported today that a number of high-up Equifax executives, including Equifax Chief Financial Officer John Gamble; President for U.S. information solutions Joseph Loughran; and President of workforce solutions Rodolfo Ploder sold shares at high prices on August 1st and August 2nd. Equifax says it found out about the breach on July 29.

CNBC reports that the head of Equifax's security group, John J. Kelley III, made $2.8 million in 2016.

A.G. Schneiderman says that Equifax consumers who think they may have been affected by the breach can contact his call center at 866-447-7559, and should also check their credit reports, consider placing credit freezes, and monitor their credit card and bank statements. Though Equifax has set up a help site for consumers, language in the site's terms of service agreement prohibits help site users from participating in any class action lawsuits against Equifax, so you may want to reconsider.

PSA: If you check Equifax's site to see if your data was stolen, you *waive your rights* to sue Equifax or be part of a class action suit. pic.twitter.com/p4AlmmLQ3r — Zack Whittaker (@zackwhittaker) September 8, 2017

Schneiderman says his office has contacted Equifax to get them to remove the language from the terms of service.