Kevin Johnson and Jessica Guynn

USA TODAY

SAN FRANCISCO — The Justice Department is expected to announce charges as soon as Wednesday related to hacking attacks that compromised millions of Yahoo user accounts, according to a U. S. official.

The official, who is not authorized to comment publicly, declined to elaborate. The Justice Department has scheduled an announcement Wednesday morning.

Yahoo declined to comment. Verizon, which is buying Yahoo's core Internet business, also declined to comment.

Bloomberg first reported the development late Tuesday.

It's unclear if the charges stem from the hacking of data of approximately 1 billion Yahoo user accounts that Yahoo disclosed in December or a separate incident that involved about 500 million accounts that took place in 2014. Yahoo has said it has evidence linking the 500-million-account breach to a state-sponsored actor.

It's new and it's bad: Yahoo discloses 1B account breach

The security breaches prompted Verizon to negotiate a price reduction, trimming $350 million from the acquisition of Yahoo for a total of $4.48 billion. The two companies will share some legal and regulatory liabilities arising from the breaches.

Yahoo CEO Marissa Mayer agreed to forgo any annual equity award she might get for 2017 because of the massive breach her company suffered in 2014.

The Yahoo board also voted to withhold her 2016 annual bonus — usually around $2 million— for the same reason. Under her contract, her equity award is not to be less than $12 million per year. Yahoo's general counsel Ronald S. Bell resigned from the company and received no payout.