Flu (Korean: 감기; RR: Gamgi; alternatively titled The Flu) is a 2013 South Korean disaster film written and directed by Kim Sung-su, about an outbreak of a deadly strain of H5N1 that kills its victims within 36 hours, throwing the district of Bundang in Seongnam, which has a population of nearly half a million people, into chaos. It stars Jang Hyuk and Soo Ae.[2][3][4][5][6]
Plot
Brothers Ju Byung-woo and Ju Byung-ki are smugglers in Seoul who find that illegal immigrants have died in a shipping container from an unknown illness. They take sole survivor Monssai and cellphone video of the bodies to show their boss in Budang, but Byung-woo becomes sick and Monssai escapes. The brothers go to a clinic where the contagion is passed on to others who spread it throughout the city.
https://en.wikipedia.org/wiki/Flu_(film)#Plot
https://www.imdb.com/title/tt2351310/