It's runtime, but I think dynamic linker. The Windows equivalent would be if a library patched some code at dllmain. Actually the Detours library in the Windows world is similar. But it's for performance; the idea is you would patch some function references based on the CPU revision to get faster code specific to your CPU.
This is a really nice windows analogy, however it goes without saying this package wasn't aiming for Windows, ironically, it chose the path (as we seen so far) of least resistance. If you're hooked to an sshd service, your golden. They put 5 checks (maybe comically) in a row to make sure it was linux I this case .. who knows what's next.
