Facebook said Friday that hackers obtained a swath of information from more than 29 million accounts, according to the Associated Press.

What happened: Facebook said the FBI is currently investigating the hack. The social network chose not to reveal who may be behind the attack, saying there’s a possibility that smaller attacks of the same nature could happen.

The company said 1 million of the 30 million people who were hacked didn’t lose any data.

Here’s how to figure out if you got hacked:

  • Visit the Facebook help center’s website here.
  • Scroll down to the light blue box, which has the headline, “Is my Facebook account impacted by this security issue?”
  • The page will inform you if you’ve been hacked or not.
  • You don’t have to change your password.

Hacked: If you’ve been hacked, there are two possibilities for what happened to you.

  • According to WIRED, 15 million people had their name, email and phone numbers all taken by hackers.
  • Meanwhile, 14 million people lost all their personal information as well as the username, date of birth, gender, devices you used Facebook on, and your language settings.
  • Hackers also receive all of your relationship status, religion, hometown, current city, work, education information, too.

More to the story: Facebook said it discovered the attackers on Sept. 25, 2018. These obtained access tokens, which serve like digital keys to allow people to hack into the Facebook platform.

  • The company invalidated 90 million accounts that were affected by the hack.

Why this matters: The Facebook hack comes as the company fights cases of fake news, misinformation and overall misuse during the upcoming midterm elections in the United States, according to the Associated Press.