NASA hasn't declared what the rock is just yet, but the Perseverance team tweeted on Wednesday, "While the helicopter is getting ready, I can't help checking out nearby rocks. This odd one has my science team trading lots of hypotheses."
Weathered volcanic rocks can look similar though NASA's guess is reasonable given all the meteoric rocks strewn around. I'm holding out for what analysis of the mineralogy (if that is possible) tells us . . . until then I'm only going as far as "weathered" AND "shot at"! <smile>