This week, a group of hackers released a list of about 5 million Gmail addresses and passwords. This list was not generated as a result of an exploit of WordPress.com, but since a number of emails on the list matched email addresses associated with WordPress.com accounts, we took steps to protect our users.

We downloaded the list, compared it to our user database, and proactively reset over 100,000 accounts for which the password given in the list matched the WordPress.com password. We also sent email notification of the password reset containing instructions for regaining access to the account. Users who received the email were instructed to follow these steps:

  1. Go to WordPress.com.
  2. Click the “Login” button on the homepage.
  3. Click on the link “Lost your password?”
  4. Enter your WordPress.com username.
  5. Click the “Get New Password” button.

In general, it’s very important that passwords be unique for each account. Using the same password on different web sites increases the risk of an account being hacked. Now would be a good time for all users to go through all online services and set distinct, strong passwords for each.

It’s also a good idea to enhance account security by enabling two-step authentication on services that support the feature. Two-step authentication can be set up on WordPress.com by following these steps:

  1. Browse to WordPress.com.
  2. Hover over the user avatar at the top right of the screen.
  3. Click “Settings.”
  4. Click “Security” from the submenu.
  5. Follow the instructions provided there.

We checked the accounts of 600,000 other WordPress.com users whose email addresses were included in the list. Since these users were not immediately vulnerable, we did not reset their passwords or send emails but will be enabling a notification in their dashboards so that they can assess the security of their passwords at their leisure and with all of this information in hand.