Strange Digital

I was tuning around this morning at about 0730 Zulu, and I flipped my radio to 5 MHz. I stopped on 5.332, where I heard a strange digital sound, rapidly pulsing. I opened up Digital Master 780, and took a couple of screenshots of what I heard. If you can identify this mode, I would be very interested in finding out what it is, so I can receive and possibly transmit it!

The two squiggley lines are non-related. The vertical lines are the signal as depicted by Digital Master 780’s waterfall display. Click the image to view larger.