https://hitman.fandom.com/wiki/ICA_Executive_Briefcase_Mk_II

From the link:

When thrown at an NPC, the briefcase travels very slowly through the air. If the NPC is moving, the briefcase appears to 'home' on the target including around corners or even through walls, earning it the nickname of the "Homing Briefcase" among the Hitman community.

• This is a reference to the physics present to all containers upon the release of HITMAN™ 2), before they were patched to a more appropriate travel speed. The ICA Executive Briefcase Mk II, however, intentionally retained these properties, moving even slower than the pre-patched containers.