Credit bureau Equifax is expected to pay about $650 million to settle federal and state investigations and consumer claims relating to a data breach that exposed sensitive information belonging to 145 million people, according to two people familiar with the settlement discussions.

The breach, which Equifax revealed in September 2017, included Social Security and driver’s license numbers and was one of the most severe exposures of Americans’ personal data. It drew widespread condemnation from lawmakers, law enforcement agencies and consumers. It also prompted the sudden departure of Equifax’s chief executive and sent the company’s stock price tumbling, though it has since made back most of its losses.

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A $650 million payment would be in line with what the company expected. In a recent financial filing, Equifax said it had set aside $690 million to cover the anticipated legal costs of the hacking.

Attackers siphoned data out of Equifax’s computer systems over the course of months, through a known software vulnerability that inadvertently went unpatched. Who stole the data remains unknown — the company and law enforcement officials have not publicly attributed the crime, and cybersecurity experts have not seen the data surface in the kinds of online forums in which stolen personal data is often bought and sold.

Most of the roughly $650 million payment would go toward compensating consumers for costs associated with the data breach, according to those familiar with the settlement discussions.

Federal and state agencies — including the Federal Trade Commission, the Consumer Financial Protection Bureau and at least 48 state attorneys general — are expected to announce details of the settlement Monday. One of the people familiar with the settlement said Equifax would be required to take measures aimed at protecting its data. Under a previous consent order with eight state regulators, Equifax already agreed to comply with new rules aimed at making its data more secure.

Plans for the settlement were reported earlier by The Wall Street Journal.

Equifax is facing a lighter financial penalty than some other corporate transgressors, like Wells Fargo, which paid $1 billion last year to settle charges from federal regulators for forcing unnecessary products and fees on unwilling customers. Federal laws give regulators like the FTC, which has primary supervision responsibility over data security, limited ability to impose fines, which has become challenging as the number and severity of data breaches grow.

Wyatt Jefferies, a spokesman for Equifax, declined to comment.