An LLM Trained to Create Backdoors in Code – Source: www.schneier.com

Clive Robinson • February 20, 2025 12:56 PM

@ Bruce, ALL,

With regards,

Scary research

The putting of backdoors in others code is now a fairly standard “supply chain attack”. So predictable and in theory can be mitigated (think an extension of the old AV techniques).

What I find more disquieting is the fact that “anything could be put in” not just “backdoors” that are at least recognisable by code signature or behaviour signature.

Do you remember back to when “binary chemical weapons” were the “shock horror” story. Put simply it opened up the possibility that two fairly safe and useful chemicals when mixed would become deadly.

So consider the idea of malware that consists of two separate pieces of software. Run either on it’s own and you get useful functionality, run the two together and something nasty happens.

That is neither piece of software contains code that would get flagged as concerning under code audit/review but together then as the Platters used to sing,

“Smoke gets in your eyes”.

I developed a prototype of this several years ago and I used a shared resource (post script printer) for signalling and data passing to get KeyMat from a secure process to an insecure process in effect using a time based side channel as the comms channel.