Official Google Webmaster Central Blog: My site's been hacked

Webmaster Central Blog

Official news on crawling and indexing sites for the Google index

My site's been hacked - now what?

Monday, April 07, 2008

Written by Nathan Johns, Search Quality TeamGoogle Webmaster ToolsQuick Security ChecklistStopBadwareTrends in Badware 2007this postGoogle Online Security BlogThe Ghost in the Browsertechnical reportGetting your site off-line

Take your site off-line temporarily, at least until you know you've fixed things.*

If you can't take it off-line, return a 503 status code to prevent it from being crawled.

In the Webmaster Tools, use the URL removal tool to remove any hacked pages or URLs from search results that may have been added. This will prevent the hacked pages from being served to users.

Damage Assessment

It's a good idea to figure out exactly what the hacker was after.

Were they looking for sensitive information?
Did they want to gain control of your site for other purposes?

Look for any modified or uploaded files on your web server.

Check your server logs for any suspicious activity, such as failed login attempts, command history (especially as root), unknown user accounts, etc.

Determine the scope of the problem—do you have other sites that may be affected?

Recovery

The absolute best thing to do here is a complete reinstall of the OS from a trusted source. It's the only way to be completely sure you've removed everything the hacker may have done.*

After a fresh re-installation, use the latest backup you have to restore your site. Don't forget to make sure the backup is clean and free of hacked content too.*

Patch any software packages to the latest version. This includes things such as weblog platforms, content management systems, or any other type of third-party software installed.

Change your passwords - https://www.google.com/accounts/PasswordHelp

Restoring your online presence

Get your system back online.

If you're a Webmaster Tools user, sign in to your account

If your site was flagged as having malware, request a review to determine whether your site is clean
If you used the URL removal tool on URLs which you do want in the index, request that Webmaster Tools re-include your content by revoking the removal.

Keep an eye on things, as the hacker may try to return.

Webmaster Help Center guidelines

If your site's been flagged by Google as serving malware, we'll alert you when you visit Webmaster Tools.

Don't forget about the Google Webmaster Help Group; it's full of extremely knowledgeable users, and Googlers as well. For a nice, on-topic example, check out this thread. There's also a Stop Badware group.

Matt Cutts recently posted Three tips to protect your WordPress installation on his blog, and there are lots of great comments below the post as well.