Quora the Q&A website has had a data breach affecting over 100 million registered users. The names and email addresses have been taken, the hackers also got access to encrypted passwords, and questions people had asked.
Users are advised to to reset their password and will be prompted to do so when they next try to log in.
We recently discovered that some user data was compromised as a result of unauthorized access to one of our systems by a malicious third party. We are working rapidly to investigate the situation further and take the appropriate steps to prevent such incidents in the future.
We also want to be as transparent as possible without compromising our security systems or the steps we’re taking, and in this post we’ll share what happened, what information was involved, what we’re doing, and what you can do.
We’re very sorry for any concern or inconvenience this may cause.
On Friday we discovered that some user data was compromised by a third party who gained unauthorized access to one of our systems. We’re still investigating the precise causes and in addition to the work being conducted by our internal security teams, we have retained a leading digital forensics and security firm to assist us. We have also notified law enforcement officials.
While the investigation is still ongoing, we have already taken steps to contain the incident, and our efforts to protect our users and prevent this type of incident from happening in the future are our top priority as a company.
What information was involved
For approximately 100 million Quora users, the following information may have been compromised:
- Account information, e.g. name, email address, encrypted (hashed) password, data imported from linked networks when authorized by users
- Public content and actions, e.g. questions, answers, comments, upvotes
- Non-public content and actions, e.g. answer requests, downvotes, direct messages (note that a low percentage of Quora users have sent or received such messages)
Questions and answers that were written anonymously are not affected by this breach as we do not store the identities of people who post anonymous content.
The overwhelming majority of the content accessed was already public on Quora, but the compromise of account and other private information is serious.
What we are doing
While our investigation continues, we’re taking additional steps to improve our security:
- We’re in the process of notifying users whose data has been compromised.
- Out of an abundance of caution, we are logging out all Quora users who may have been affected, and, if they use a password as their authentication method, we are invalidating their passwords.
- We believe we’ve identified the root cause and taken steps to address the issue, although our investigation is ongoing and we’ll continue to make security improvements.
We will continue to work both internally and with our outside experts to gain a full understanding of what happened and take any further action as needed.
What you can do
We’ve included more detailed information about more specific questions you may have in our help center, which you can find here.
If you were affected, we will update you with relevant details via email.
While the passwords were encrypted (hashed with a salt that varies for each user), it is generally a best practice not to reuse the same password across multiple services, and we recommend that people change their passwords if they are doing so.
It is our responsibility to make sure things like this don’t happen, and we failed to meet that responsibility. We recognize that in order to maintain user trust, we need to work very hard to make sure this does not happen again. There’s little hope of sharing and growing the world’s knowledge if those doing so cannot feel safe and secure, and cannot trust that their information will remain private. We are continuing to work very hard to remedy the situation, and we hope over time to prove that we are worthy of your trust.