There might be dark days ahead for internet destination Yahoo. Sources recently told journalist Kara Swisher of Recode.com that the service was set to announce a massive breach in security that may have compromised the information of hundreds of millions of users.

That confirmation came today, with the service indicating that more than 500 million Yahoo user accounts may have been exposed.

Reports of the hack began circulating in August, when a known cybercriminal named “Peace” bragged about securing the passwords and personal information of 200 million Yahoo accounts. The data included birth dates and email addresses and was allegedly being offered for sale to identity thieves online. Yahoo maintains that no encrypted information—like credit card numbers—was retrieved.

if you have a Yahoo account, now would be a good time to change your password, and read up on these tips for more smart ways to protect your information online.

News of the hack comes just as Yahoo is set to finalize a sale to Verizon for an estimated $4.8 billion.

[h/t Recode]