Writing on WordPress.org, Matt Mullenweg said “today the WordPress team noticed suspicious commits to several popular plugins (AddThis, WPtouch, and W3 Total Cache) containing cleverly disguised backdoors. We determined the commits were not from the authors, rolled them back, pushed updates to the plugins, and shut down access to the plugin repository while we looked for anything else unsavory.
We’re still investigating what happened, but as a prophylactic measure we’ve decided to force-reset all passwords on WordPress.org. To use the forums, trac, or commit to a plugin or theme, you’ll need to reset your password to a new one. (Same for bbPress.org and BuddyPress.org.)
If you use AddThis, WPtouch, or W3 Total Cache and there’s a possibility you could have updated in the past day, make sure to visit your updates page and upgrade each to the latest version.”
Read more: http://wordpress.org/news/2011/06/passwords-reset/