[Kaiten]

Well since they have a web shell, they are most likely running some sort of *nix.
So if you had a botnet, for example Kaiten IRC, you would be able to download your file (Kaiten.c) and execute the file.
Which would then link that system(The router.) To your botnet, which would allow you to remotely execute commands from the IRC, such as DoS attacks.

Good idea... I should test that one day soon!

Thanks

No problem, and good luck!