Google has released its big list of algorithm changes for the month of May. There are plenty of interesting changes of note, but the first one on the list is:
Deeper detection of hacked pages. [launch codename "GPGB", project codename "Page Quality"] For some time now Google has been detecting defaced content on hacked pages and presenting a notice on search results reading, “This site may be compromised.” In the past, this algorithm has focused exclusively on homepages, but now we’ve noticed hacking incidents are growing more common on deeper pages on particular sites, so we’re expanding to these deeper pages.
Don't create pages with malicious behavior, such as phishing or installing viruses, trojans, or other badware.
Obviously, this could occur as the result of hacking.
A few months ago, Google improved malware detection in tis ads too:
Google is also alerting users about their malware-infected machines.
This week, Google even began letting users know when their accounts are being targeted by state-sponsored attacks.