The first step for my group with data as potentially dangerous as that would be to go to ground hardcore, that's the sort of drek that gets you square in the crosshairs of the AAA Corps at even a rumor you might have seen it. The corp actually developing it will likely throw everything it has at you to get it back, or destroy it, because they are finished if their involvement comes out. The Dragons themselves will definatley be out for it too and this is the sort of rare threat that can cause a temporary alliance between them, which is BAAAD news if you like breathing.
With data as hot as that you need to thouroughly cover your backs and be insanely carefull, I know prime runners who wouldnt touch that data. I would consider setting a deadman trigger or 4 to make the data public as insurance and letting the developer know they will activate and leak the data if they take ANY action towards you to buy some time. Then probably contact the Draco foundation hash out a protection gig for your group and some pay, making sure you have leverage so they need you alive. If the dragons unite you want to be on their sweet side. You might need to agree to memorywipes or something similar once the data is handed off as well so make sure you have damn good reminders who might be gunning for you if it's necessary.
In short, go to ground, setup deadman switches, act quickly, choose a side strong enough to protect you from the fallout. I would also have totally new identities ready for the team should anything go wrong at all.