Abbas was given a release from the final year of his Sydney FC contract on 3 May before putting pen to paper with the K-League outfit.
The Iraqi international played 72 games for Sydney FC after joining the club in 2012 but battled with a serious knee injury in 2014 which sidelined him for more than a year.
“I am very sad to be leaving Sydney FC but this is a good opportunity overseas” Abbas said on his Sydney departure.
“I have really enjoyed my time here and I am so proud to have represented the fantastic members and fans at Allianz Stadium.
“The support I have received throughout the years has made me proud to be a part of the Sky Blue family, and the club will always remain in my memory.”