Hold on to your hats, this new router security flaw is a doozy. The important question you should be asking right now is what kind of wireless router do you use? If it's one specific, popular model, you could have a serious problem.
This newly discovered flaw lets anyone mess with your DNS settings to send you viruses and even remotely control your computer.
The router in question is a D-Link model, the DSL-2740R. A Bulgarian security researcher discovered the flaw in the router's firmware, ZynOS, but didn't alert either the firmware or the router/modem company. Instead, he released the information online directly, without giving the company a chance to offer a fix.