- the target is some server (> 2010) that could be running any OS
- the attacker has gained access to everything remotely, (with maybe some physical access as well)
Is it possible for an attacker, through only software means, to leave an irreversible software artifact on the target? If so, what is the nature of the target and the greatest extent of the damage?
Examples of an irreversible software artifact: something that can't be removed with system restore or formatting hard drive (e.g. maybe a BIOS change?)