The big leak contains unreleased and pre-release content from Bungie-era Halo games from Halo CE up to Halo 3 and Reach.

After Insomniac Games, Rockstar, and the Pokemon Company were all hit by major leaks in recent years, Halo Studios has now fallen victim to a similar situation where almost 25 years of vaulted content from the shooter series has spilled onto the internet.

The team claims that Microsoft neither paid them for their efforts nor provided resources and it appears that someone else decided enough was enough so a massive amount of content is now out in the wild for the PC community to do with as it wishes.