In the Halloween 2017 Event new masks were added to the game.
Seven Deadly Sins Masks
The Cursed Kill room comes with 7 sinful masks to collect. To get a mask you need to open some safes first so get cracking.
I already played the new Cursed Kill Room Heist plenty of times:
We are releasing the Cursed Kill Room a limited time event heist. During the next two weeks you can go in and crack open as many safes as you can. The timer only counts down when you are not protecting a safe, so be fast when securing the loot. You can gain extra time by shooting cops.
Do I need to open the safes from this new heist? Or are they talking about the usual safes that drop randomly once per week?