I originally posted this to the AusNOG mainling list, but I realised that maybe this needs some more discussion, as I'm always willing to entertain the possibility that I'm wrong!

I've been doing some research on my own, to see if ANYTHING corroborates this, and I'm coming up empty handed. (This is the bonus of being unemployed!)

Let's go through a few assertions in the original article.

It was an extremely small chip ('grain of rice'), disguised as a signal coupler (which has, at most, 4 pins)
It was able to alter the OS running on the machine
It was tied into the BMC
It was able to connect to things, AND receive connections from things.
Unfortunately, those things just don't add up. The smallest standalone computer that I can find is from IBM - https://bit.ly/2GLm0K6 - which is 1mm2.

That does not include any external communications pins (apparently), as it's all self contained.

You can't just wave a magic wand and say 'It was connected to the BMC, so it could do all these things'. Especially if it only had 4 pins - 2 of which would be power, and the other two would be 'rxd' and 'txd' - But what does it connect to? How does it recieve connections? Does it tap into the BMC and make it do stuff? This just doesn't add up.

But, OK. Let's say it actually was wired directly into the BMC NIC. That would only need 4 extra pins, right? Welllllll... no. You can't just run a second network connection in parallel. You need a switch, or a hub, SOMEWHERE. If it was on the motherboard, someone would look and go 'Why is there a switch on my ILO?'. If there WASN'T a switch/hub chip on the motherboard, that means that it would need to be inside this magic chip. But that now increases our pin count requirements to vcc/g/rx/tx PLUS 8 more pins for NIC coming in, and NIC going out.

The next problem is, the person who plugged it in would immediately notice that it's only linking at 100mbit, rather than 1gb, so you actually need 16 more pins now, so you're up at 20 pins, bare minimum.

So, there's no possibility, at all, of this tying into the actual network interface itself. If this actually happened, which I strongly disbelieve, the only thing it could do would be to talk to the BMC directly. Via Serial.

But that means there's some MASSIVE security issue with the SuperMicro BMC, where there is some method of defeating all the security they put into it to stop US from doing things with it, that would then let it be zombied by this tiny, implausible chip.

So I don't know WHY Bloomberg is pushing this, especially with extremely vocal and explicit denials from all the parties involved. I'm calling this 'fake news' and my first hypothesis was that it's something do with with the US Government being annoyed at China, but I try to avoid conspiracy theories, and I think we'll probably find out it was 4chan trolling some bloomberg reporter, for the lulz.