Add this step to hardening your home and work networks against attacks from the Internet:
- Turn your router’s UPnP off.
I previously thought that making sure all ports on the router were closed was sufficient to block attacks from the Internet, but it is not. If your router supports UPnP, which most do now, you should disable this feature as recently reported by Daniel Garcia at H-Report.com:
If you can disable UPnP on the WAN side of the router, do so. If this isn’t possible, disable UPnP completely on the router. UPnP is rarely needed by most users, but online gamers may benefit from UPnP to more easily connect to online gaming networks.
This article shows how to turn off UPnP in common Linksys routers: