Lately Google search results have been reporting sites that may have been hacked or that might contain drive-by downloads. Underneath the search result you see a little “This site may be hacked” or “This site may harm your computer.”
Google’s support page for webmasters whose sites show this message is quite detailed and demands a lot of technical expertise to follow (especially in shell scripting). Webmasters using shared hosting would normally expect their hosting companies to assist with this. There is a possibility that all the sites on a particular shared hosting server could be affected.
I saw this on a popular site yesterday (will not identify), and visited the site on a device I don’t use for critical purposes. The site looked normal. It was a blog, and it could have been that the somewhat unusual verbiage and site organization fooled the engine. I don’t see the result with Bing on that site, only Google.
A few months ago, one of my two Wordpress sites had an issue when a spam comment loaded on top of the web page. I have Askimet but somehow the service missed this one. The problem went away when I, as administrator, merely deleted and marked the comment as spam. The site did not get flagged by Google.
Sites that are not frequently updated might be more vulnerable. The possibility of illegal content could be a legal risk for some webmasters. But around the country, news media show scattered reports of sites hacked with radical religious propaganda.
In 2002 two flat files on an old Apache legacy site (one file discussing nuclear terror) were hacked.