League of Legends hardware bans are the device-level case: the computer is flagged, and a new Riot login on that machine is blocked as well. Riot’s client can share hardware checks with other Riot titles on the same PC.
The sign is immediate refusal on a fresh account, before a normal match starts. That pattern points at the hardware ID.
The League spoofer changes the hardware profile the PC presents, so the banned identifiers are not what the client reports.