Most of the readers of this blog read it in a browser. Modern browsers are incredibly powerful and are literally computers within computers. Unfortunately, this means that the same kind of malware that haunts the operating system on which a browser runs can do the same in the browser.
Java, a computer language that was designed to run on different operating systems, was a natural fit for browsers. It also turns out to be a perfect way to introduce malware, so much so that the Department of Homeland Security recently recommended that it be disabled in your browser. How do you do that? Gizmodo has a great guide for all of the popular browsers. Check it out, and safe browsing!