Under the law, the rightful owner of stolen property can demand its return. If it's currently installed in your phone, that's your problem, even if you bought it "fair and square" - that just gives you a claim on the merchant who sold you stolen goods.

The exception to this is currency: if you're fairly paid with stolen money, you get to keep the money, regardless of whether the rightful owner is able to proof that it was originally theirs and stolen.