Google Algorithm Penalties:
Hacked Content
As if it isn't enough that your own actions (intentional or otherwise) can land your domain in the Google penalty box, you also have to be on-guard for hackers that can compromise your website's content and get your domain penalized. If a hacker breaches the security measures you have set up to protect the integrity of your domain, and adds objectionable content and/or viruses or malware unbeknownst to you, Google will penalize your site in order to protect their users and to maintain the integrity of their search results.
If your site or pages on your side are hacked Google will take the following actions:
- Red flag your domain in their database
- Remove your domain from the rankings by suppressing it in keyword searches
- They may attempt to contact the webmaster/owner via email as well as post a malware warning in the domain's webmaster tools account alerting the administrator(s) that the domain has been hacked.
Hacked content can be:
- Injected, harmful content
- Added content intended to manipulate the search engines
- Hidden content that may not be visible to you, but is clearly identified and picked up by the search engines.
The best way to keep your site from being hacked, and then being penalized by Google for having hacked content, is to take effective security measures to ensure that your domain is protected from would-be hackers.