I kind of want this to be true, but I will bet you anything it's fake.
Firstly, the source. The only references to a "Korea Future Technology" I can find lead back to this guy's Instagram account. Vitaly Bulgarov is a professional 3D graphics artist who specialises in, amongst other things, very realistic looking mech warriors.
His website makes a series of improbable claims, including that he worked for Boston Dynamics as a "conceptual and industrial designer". But in 2015 he posted a picture to his Instagram about him visiting Boston Dynamics. There is no evidence anywhere that he ever worked for them - if he did anything for them at all he'd have done some contract VFX work.
Secondly, why would a company making a project that can only have military funding allow videos to be released on some random dudes Facebook page, why wouldn't they announce as a big splash to get the company the credit?
Thirdly, in one picture there's a set of "carbon fibre legs waiting to be tested", which show no motors or metal pieces. In the other photos the legs are made of metal. Which is it?
Finally, the continuity glitches. Watch the door carefully in this video
https://youtu.be/Re6P7WP2N5w?t=28s
It's to the right of the robot. At the 29 second mark it suddenly goes from closed to open in the space of a single frame - the video backdrop is composited from multiple shots, but the robot isn't.
This is a very talented graphics artist screwing with people.