Confidential Assignment (; lit.
 Cooperation) is a 2017 South Korean action film directed by Kim Sung-hoon.
 It stars Hyun Bin, Yoo Hae-jin and Kim Joo-hyuk.
Resurrection of the Little Match Girl () is a 2002 South Korean action film.
 It was screened at the 2003 London Film Festival and was the opening film of the Fantasia Festival that same year.
The City of Violence (; lit.
 "Partner" or "Pal") is a 2006 South Korean action film co-written and directed by Ryoo Seung-wan, who stars in the film opposite action director and longtime collaborator Jung Doo-hong.
 The story re-unites three former childhood friends for their friend's funeral, which prompts two vowing to find his murderer.
Shiri () is a 1999 South Korean action film, written and directed by Kang Je-gyu.
Kim Sung-hoon (born 1974) is a South Korean film director.
 Kim debuted with the musical drama film "My Little Hero" (2013).
 His second feature was the fast-paced action film "Confidential Assignment" (2017) which starred Hyun Bin.
 A box office hit with more than 7.8 million admissions and grossing over USD56.4 million, the film was sold to 42 territories, including the U.S., the Middle East, India, the Philippines and Mongolia.
Typhoon () is a 2005 South Korean action film directed by Kwak Kyung-taek and starring Jang Dong-gun, Lee Jung-jae and Lee Mi-yeon.
A Bloody Battle for Revenge (Korean: 복수혈전 ) is a 1992 South Korean action film directed, written by, and starring Lee Kyung-kyu.
 This film is often cited as an example of failure in movie industry in Korea.
Lee Dae-ro Can't Die (; also known as Short Time) is a 2005 South Korean action film about a corrupt police officer who is told he has only three months to live, and plots his own death so his wife can collect his insurance policy.
 The film was released to South Korean cinemas on August 18 and received a total of 838,419 admissions nationwide.
Anarchists is a 2000 South Korean action film directed by Yoo Young-sik and co-written by Park Chan-wook.
 Set in Shanghai in 1924, the film is about a covert cell of insurrectionist anarchists who attempt to overthrow the Japanese government's occupation of Korea through propaganda of the deed.
 Told from the perspective of the youngest member, Sang-gu, years after the fact, the story is a sympathetic look at a group of revolutionaries through the eyes of one of their own.
Mr. Butterfly ("Nabi") is a 2003 South Korean action film.
 The film is the writing and directorial debut (and, as of 2011, only) film of Kim Hyeon-seong, sometimes credited outside Korea as Marc Kim.

Question: Confidential Assignment was a South Korean action film directed by whom?
Answer: Kim Sung-hoon