This is the covenant crate made for the fan-made halo game "Installation 01" based on the version seen in Halo Reach.
My first "interview" task to join the I01 team ended up becoming two different covenant crates as they really liked how it turned out. This did take longer than expected due to being such an odd shape to get right. This crate became known as the basic covenant crate while the second crate became known as the Brute Crate ~ https://www.artstation.com/artwork/xzq8DW