What you can see below is a screenshot of the german version of the malware warning Google is sending out right now to every search you do on it (according to some IRC channels it really seems to happen everywhere). You probably have seen it, too.
Needless to say that this is a severe problem for Google and it’s perception on how reliable they are. Twitter of course is going crazy about it.
More interesting though will be to see what this might mean in terms of internet traffic as most people probably do now know what’s going on and will not copy the link in that message to their browsers by copy/paste either because they don’t see it or they are scared to do so.
According to TechCrunch though it only seems to appear if you are logged in as a Google user, so it might in fact not be a problem of the “whole” internet. Nevertheless a big blow for Google that this could happen.
Update: It seems to be fixed now for me.
Update 2: Marissa Mayer has posted to the official Google blog to explain the situation. Seems that StopBadware.org, a non-profit organisation for detecing bad sites, has accidently added the URL / to the list of bad sites which expands to all URLs and thus marked all URLs in Google searches as being malware. According to Marissa Mayer that has been detected quite quickly and a staggered rollback has been activated. Approx. 40 mins was the duration of that problem. StopBadware has an explanation here (but it seems to be drowned in traffic right now so that I cannot read it).