Badware is software that fundamentally disregards a user’s choice about how his or her computer or network connection will be used.

A badware website facilitates the distribution of badware, either intentionally or because it has been compromised. Many, perhaps even most, badware websites distribute badware without the knowledge of the sites’ owners.

For more information, see our detailed explanation about badware or our Badware Guidelines.

Google, which is a StopBadware partner, is committed to protecting people from badware websites. A few years ago, Google developed a system for automatically identifying many of these badware sites, and they worked with StopBadware to develop standards and an independent review process to ensure this system would remain accurate and fair.

When Google detects a badware site, it inserts an interstitial page titled “Warning! This site may harm your computer” when users try to access the badware site via Google’s services (search results, Chrome browser, Google Desktop, etc.).

Google also makes it possible for third parties to check URLs against Google’s list. Firefox, for example, uses Google’s Safe Browsing API and shows an interstitial page titled “Reported attack site!” when users try to access a site that Google has detected as bad.

While it is possible to bypass these warnings, visiting a badware website may expose your computer to badware, with or without visible symptoms. This is especially true if you have not taken steps to protect your computer from badware. If your site is prompting these warnings, it is possible that your site has been infected without your knowledge.

Please read our Tips for Cleaning & Securing Your Website to learn how to find and remove the badware and to protect your site against future infection. Once your site is clean, see our instructions for requesting a review to learn how to remove your site from Google’s list of badware sites.

If your website is being reported to StopBadware’s Badware Website Clearinghouse, please clean and protect your website, and then see our instructions for requesting a review.

Firefox attempts to download an updated list of badware sites from Google’s Safe Browsing API about every 30 minutes. Sometimes, it has trouble downloading the update or incorporating updated data into the list on your computer. In this case, your copy of Firefox may still think a site is a badware site.

To confirm that Google is no longer listing your site, search Google for site:your-site-here.com (replacing your-site-here.com with the domain name of your site). If any of the results show “This site may harm your computer,” then your site is still listed by Google. Please refer to our instructions for requesting a review.

To remove Firefox’s list of badware sites, which will leave you unprotected until the list successfully downloads again, close Firefox, rename or delete the file urlclassifier3.sqlite in your Firefox profile directory (see here for information on locating your profile folder), and restart Firefox.

Disabling Firefox’s badware website warnings will increase your risk of having your computer infected by drive-by downloads and other badware. If you are willing to accept this risk, you may disable the warnings in the Firefox options/preferences by clicking the Security option, unchecking “Block reported attack sites,” and clicking OK.

Please see our guide to protecting your computer from badware.

Please see our guide to removing badware.

If you have encountered a badware application, you can tell us and the community about it at BadwareBusters.org. Just start a discussion and describe the software, where you found it, and what you believe makes it badware. (If you are not already a member of BadwareBusters.org, you will be required to create a free account.) Feel free to refer to our Badware Guidelines as your write your report.

We are working to create a system for reporting badware websites, but it’s not ready yet. For now, please report badware sites to Google.