Abu Mosa (presumably a nom de guerre) was a press officer for the Islamic State. In a documentary video made by Vice News reporter Medyan Daireh, he threatened the US and said "we will raise the flag of Allah in the White House". He also threatened to "liberate Istanbul".
He was killed by an air strike on 22 August 2014 by the Syrian army in an attack for al-Tabqa air base in Raqqa Governorate during the Syrian Civil War. It was confirmed by U.S. Department of State.