Today Bloomberg published an article about a newly discovered hardware trojan found on Supermicro boards. The article is titled "The Big Hack". Unfortunately the article was not very specific about how the trojan chip operates. It says only that it modifies data being held in "temporary buffers" holding memory destined for the CPU. This might refer to buffered ECC memory chips or maybe something else. There are a lot of possibilities.
Also, the article does not indicate how being able to intercept instructions to the CPU would allow it to transmit data from the device.
Another vague aspect of the article is that it says the trojan chip "modifies the operating system core". I assume by this they are referring to a Linux kernel. I can guess at how such a chip might do this, but does anyone have any more specific information on how the mechanism works exactly?