Four heroes step foot into a greater frontier, the moon. And with them, believe it or not, an entire hoard of brain-eating zombies.
There's a whole lot to explore here, as well as a variety of new tools to play around with. Of them, Hacker may be the least understood, a tool that drastically changes the flow of the match.

Hacker:

Once you hit the labs, check the various office desks for Hacker. New to Moon, the hacking device has a variety of uses around the space station. First and foremost, only one player can pick up Hacker, taking the place of their P.E.S. Hence, it's vital to be aware of your current environment. Stay in pressurized areas, and only go outside for brief periods of time to avoid choking.

Windows:

Hack broken down windows to repair all pieces at once for 100 points. Just don't get greedy – hack the same window more than twice in a round and you're instead penalized 300 points. For max points, repair all but one piece and then hack.

Mystery Box:

If you're not happy with the first weapon, you can hack for a second spin for only 600 points. If you don't like the second, hacking it refunds 950 points, as well as making the weapon available to your other teammates for a short period of time. Additionally, inactive Mystery Box locations can be hacked for a single spin at the cost of 1200 points.

Perks:

Double Tap not turning out to be as useful as you thought? Hack any Perk machine that you've accessed (and you still own the Perk from) to return it for a full refund.

Wall Weapons:

Hacking wall weapons causes the ammo refill costs to switch. Refilling ammo for the normal version of the weapon now costs 4,500 points, while refilling the Pack-A-Punch version is only as costly as the weapon's pre-hacked default ammo. This is incredibly useful, and obviously should only be used after Pack-A-Punching the chosen weapon.

Pack-A-Punch:

Hack the Pack-A-Punch to gain 1,000 points and close the gates surrounding the machine for a short period of time. Warning: this is extremely dangerous if you don't have a way out when the gates re-open about 30 seconds later!

Power Ups:

Don't like the power up that just dropped? Hack any dropped power up for 5,000 points to transform it into Max Ammo. Hack Max Ammo to create Fire Sale. Very useful in later rounds when ammunitions can become scarce at a moment's notice.

Doors:

Open doors at only a fraction of the original cost. Hacking doors takes a very long time, and therefore requires that the player only hacks in pressurized locations, and has ample cover from teammates. Best done at the end of a round with crawlers holding off the next wave.

Teammates:

Sharing truly is caring. Hack another player to hand over 500 points. While the idea of giving up points might not sit well, consider that unprepared and ill-equipped teammates struggle in the later rounds, making it more difficult for the whole team to succeed.

And More…

These are but a few of the known uses and effects for Hacker. Treyarch isn't going to give everything away, so get out there on september 23 and experiment as soon as it comes out for PS3. You might just get blown away with what you discover.