I'll warn you straight up, you're letting yourself in for a hell of game-mastering. It seems like a fun idea, but I've seen this sort of thing DESTROY groups, permanently - as in hard feelings ten years later. It'd be better to run a game where the players hating each other is built in, like Paranoia, rather than one like Shadowrun where professionalism is the core group binder.
I did something like this once, and it worked really well. To be fair, I only did it the once, and it was to introduce a character to the group.
This, combined, is the key - to do it, to set it up and run it, but to be aware that being ready to pull a gun on your teammates at a moment's notice is essentially detrimental to the game. Set up a story arc in which the PCs - you had better know their motivations by now, as well as which buttons to push with your players - have somewhat conflicting motivations. Players F, G, and H care about and want to help the ABC people, and is willing to take the cash hit, while Player K needs that cash, dammit, or else XYZ happens to their PDQ - or XYZ just gets
closer to happening, because they can't pay off That Guy. That starts setting up tension - a difference in options. Push it gently into becoming an increasingly important issue - especially if you can continue to make it the ABC People on the one side, and That Guy on the other. Eventually, though (if you're doing your job right, sooner rather than later) you need to allow the tension / paranoia to be resolved, and here's the kicker - it has to be resolved in such a manner that it binds the team even closer together. That Guy turns out to be the one turning the crank on the ABC People, because he knows that F, G, and H are tightly involved, and that K works with them, and if he impacts K's bottom line, he can put K into his pocket for good.
Or push it a bit further - make it so that K
is forced to drop into That Guy's pocket. There's your paranoia; you have F, G, and H wondering if K is going to do something bad to them because he's taking orders from That Guy, and K is wondering if F, G, and H are going to pre-emptively whack him because he's so indebted to That Guy that they're, well, paranoid. You can back off on that, push it from game to game. Take your cellphone into the bathroom, call up the player of K, and the first thing you say to him/her is "This phone call is in-character. I am That Guy. Act appropriately." And then RP over the phone with K, forcing him to either try to conceal the contents of the call from the rest of the team, or else to get all 'go ahead, I don't care' on them. This works really well if the bathroom is some distance away from the gaming area, so that they can't hear you talking. It works ESPECIALLY well if you can get K to 'blow up' and shout some, because then you can come out and ask "I heard shouting, what was that about?"
But again, all this needs to be resolved in a way that binds the group together better. The rest of the group offers to help K get out from under That Guy's thumb, or whatever. But every party-stress idea needs to wind up with a 'stress makes the binding tighter' kind of event.