[Thorrez]

That sounds repayable though. If I did a tcpdump of the attacker attacking my system, I could replay that attack against someone other system. For it to not be replayable, there needs to be some challenge issued by the backdoored sshd.

Of course since the backdoor was never widely deployed and is now public, I think it's unlikely the attacker will attempt to use it. So whether it's replayable doesn't have a practical impact now. I'm only asking about replayability because I'm curious how it's unreplayable.