Melee attack with high damage.
The current meta sub-weapon!
It is possible to use the knife to slash or throw it at the opponent. The knives are not limited, so they can be infinitely thrown, with the limitation that previous knife disappears when you grab a new one.
Damage dealt when punched with it is 220 hp which is higher than the boost punch damage of most runners. It also destroys Legacy's shield with one hit, just like punching.
Damage dealt when thrown was recently nerfed and is currently 80 hp. Throwing the knife at Legacy's shield does not destroy it with a single hit, but it does 100 damage to the shield.
Some miscellaneous stats:
This is one popular attack style with the knife that enables you to basically punch with two hands simultaneously.
Hold knife in one hand and have the other hand empty. Do the punching action with both hands.
When you are close to the opponent, but not close enough to punch them, the knife can be a good mid-range weapon to use by continuously throwing it at the opponent. This does some damage and slows down the opponent.
This tactic used to be more popular before the nerf that lowered the damage and knockback.