Ever done a search at Google and get a message saying you need to type some characters to keep searching? Those characters are called a CAPTCHA, a method designed to help someone prove they aren’t an automated program hitting Google. Sometimes Google can mistake a human for programs like these, and the Google Security blog sheds more light today on how this can happen.
Google explains that a CAPTCHA can be triggered by automated processes sometimes caused by worms, proxy search traffic going through infected computers or DSL routers, or from some SEO ranking tools. It also says that it has seen an increase in malware being installed on computers that perform these types of automated queries.
If you ever get one of these CAPTCHAs, you simply need to verify yourself by entering the characters to continue searching. But you may also want to scan your computer for viruses and malware.