Why in the world would that specific 3x3 matrix be a trigger for an attack? Are they trying to find someone doing some particular kind of numerical analysis?
Perhaps they just need a way to sneakily activate it? Or perhaps they have a target application which they know uses that. This method suggests a supply chain attack where a valid contributor to a library 'accidentally' includes this package and the hack carries out before anyone notices.
My guess is that it's crypto related but of course it could be anything.
I would assume it’s actually so they can allow it to spread before it gets activated. Then do something that affects the entire chain of package dependencies
A status code for (industrial/the-man) equipment? You could target specific environments by activating on obscure error codes that can be remotely triggered.
Aka If someone from the outside can make your equipment emit X internally, they can target X in some way.
This matrix is not a condition, it’s a key. JSON.stringify with it’s data goes to the scrypt as a password and that creates an AES-256-GCM key. There is no if, every other input won’t decrypt. That’s why no one will get payload from the package without knowing the exact input.
Presumably it's so it can be used as a subdependency for setting up an attack in a popular, legitimate package, e.g. via a pull request. The code in the legitimate package would not arouse suspicion at all.