Did you know SD cards have a CPU?

[jhu]

and you can run arbitrary code on them. Or at least some of them.

 

[dave_the_nerd]

Well... I did not. But pretty much everything has a CPU, so this doesn't really surprise me.

 

[Rakehellion]

A memory controller? I knew that.

You can also install malicious code on the controller of any USB device.