A private company owned by the very people who apparently did the breach. Dmitri Alperovitc is Russian and owns Crowdstrike, the company that did the 'investigation'.
I'm not saying they did it, and honestly I don't care one way or the other but hiring the people who (allegedly) hacked you to find out who hacked you is the epitome of stupidity.
Going by what we see of the FBI they absolutely reek of incompetence, paying $1 million to unlock an iPhone is another example!
(edited: typo)