Basically any process that uses the new video frameworks (the QuickTime X ones, not QuickTime 7) - if they touch this video at all, they crash immediately. Mac OS only. iOS is exempt. I had my friend send me the video in a message from his phone to my Mac - I could no longer open Messages.app, because as soon as it loaded his message with that video, it crashed. It will cause Safari tabs to crash over and over again as they keep reattempting to load it. It crashes QuickLook immediately. It's about 22 KB and I came across it 100% purely accidentally. It contains only audio. QuickTime 7 Player has absolutely no problem at all playing the file. Not sure what to do with it.