Google recently announced they are highlighting or providing a link within search results for sites that have been compromised. Exactly how they determine this or what the criteria who knows for sure.
Whether this is a good thing or not I am not sure either. They probably have good intentions with it. But, after reading up on it and looking at it more it really doesn't do a whole lot.
As far as I can tell when you see the Google search results like normal, if a site is compromised they put a little link under the title. It will say something like "This site may be compromised". If you click that it will take you to an explanation or article in Google help center with more details. But, if you click the normal site title in the search results you end up on the potentially compromised site anyway.
The "This site may be compromised" link is so small and hard to see you will have a difficult time even noticing it in most cases.
So how this will be helpful I am not sure. I guess if you are the owner of the site and searching for your own pages maybe you will see this and realize something might be up with your web site. But, how many people do this on a regular basis? Not too many I'll bet.
At any rate it is kind of interesting. I would like to see if that is all it is going to do or if they change or improve on it.
More info from Google here:
New hacked site notifications in search results
Screenshot - example: