Do you have Linksys brand router E4200, E3200, E3000, E2500, E2100L, E2000, E1550, E1500, E1200, E1000,E900 you may be at risk!
There is a there's a worm out there exploiting an authentication bug in the Cisco firmware that, If you have enabled remote administration on port 8080 -- even with a good password you could be at risk. The WORM rewrites the firmware to infect the router, and then -sets the router to scan zillions of other IP addresses looking for other systems to infect.
Patch you system with the latest Firmware, and disable remote management.
You can go here. on the SANS Site to learn more about this.