The New York Times is reporting that Manafort is "working for allies of the leader of Iraq’s Kurdish region to help administer and promote a referendum on Kurdish independence from Iraq." The U.S. Govt opposes this move because it could "destabilize" Iraq and hurt the regional fight against ISIS.
Oh, and this lobbying work started, ironically, right around the time of FBI home raid. Clearly, Manafort is not too concerned with Mueller and his threats of indictment.
This kind of work may require a Foreign Agents Registration Act (FARA) filing which appears to now be done yet. Jason Maloni, Manafort's spokesman, said his client “does not discuss his current or future clients. If his work requires registration with FARA, Mr. Manafort will comply with the law." Sure he will.