The FBI has arrested a Chinese national who is facing charges related to the malware used in the 2015 data theft from the Office of Personnel Management computer systems, U.S. officials briefed on the investigation said Thursday, according to CNN.

The arrest was made Wednesday after the man entered the U.S. to attend a conference, according to the officials. He faces charges related to creation of the Sakura malware, which the FBI has said was used the breach.