This question already has an answer here:
In the first part of this YouTube video, you can see an aircraft supposedly flying 4x faster than the surrounding aircraft, at the time the Malaysian 777 went missing.
After replaying this on Flight Radar 24, KAL672 departs Kuala Lumpa a short while before MAS370. It then does a 180, flies back towards the airport, then appears to do another 180 and rockets across the ocean:
Essentially, my question is, what is this oddity that FR24 is showing? (to ward off conspiracy theorist nuts).