Yahoo confirmed on Thursday that at least half a billion user accounts had their information stolen in a "state-sponsored" cyber attack that is thought to be the largest Internet breach to date.
The stolen data included names, email addresses, telephone numbers, dates of birth, and encrypted passwords of at least 500 million accounts that were breached from the company’s network in late 2014, Yahoo said in a statement.
The company said the attack did not capture sensitive financial information like bank account information and credit card data.
Law enforcement authorities are investigating the breach.
"Online intrusions and thefts by state-sponsored actors have become increasingly common across the technology industry," a Yahoo statement said. "Yahoo and other companies have launched programs to detect and notify users when a company strongly suspects that a state-sponsored actor has targeted an account."
Reports of a potential hack surfaced last month. A Yahoo spokesman refused to confirm or deny the alleged breach, telling NBC News in August that the company was "aware of the claim" and "committed to protecting the security of our users’ information."
The breach could have implications for the company as it moves to sell its Internet operations and land holdings to Verizon in a $4.83 billion agreement announced in July. Verizon said it was notified of the breach in the past two days.
"We understand that Yahoo is conducting an active investigation of this matter, but we otherwise have limited information and understanding of the impact," a spokesman for Verizon said in a statement. "We will evaluate as the investigation continues through the lens of overall Verizon interests … Until then, we are not in a position to further comment."