It's not pretty when a Web site gets a "this site may be compromised" or "this site may harm your computer" status note. Many webmasters and Web site owners can be at a loss of what to do in these situations.
For this reason, Google has launched "Help for Hacked Sites" informational series, which has a dozen articles and videos aimed to help people avoid having their sites hacked and also teach them how to gain back control of compromised sites.
The topics covered include why cybercriminals hack Web sites, background information on spam and malware, working with a Web host to recover the site, how to clean and maintain a malware-free site, and more.
Google has several initiatives to cut down on hacking. It launched an ongoing vulnerability reward program in 2010 where the company offers dollar rewards for techies to hack into its Web services as a way to learn how best to curb hacking, bugs, and vulnerabilities.
Here's Google's "Help for Hacked Sites" overview video on how and why sites are hacked: