I would try reinstalling the driver for the wireless device in your computer and download, install, update and run Malwarebytes.http://download.cnet.com/Malwarebytes-A ... tag=button
It is free and works well.
...had another thought or two...
Call your ISP and have them "ping" your modem. They will be able to tell you if it is good or failing. I did this and found out it was failing and they replaced it for free. If it isn't the modem it may be all you need to do is flash the firmware chip in the router to fix this issue. If that doesn't help you may either have a bad router and need to replace it or it is in fact maleware causing this issue.