jungle malphite pretty simple, you want to build armor simply because at full rank your ground slam(e) spell splash damages for 50% of your armor as added magic damage, this coupled with the fact that your w spell stacks armor as well makes your aoe very powerful. for ganks you want to cast Brutal strikes(w), then ulti in, then use ground slam(e) for damage, follow seismic shard(q) to chase, then ground slam(e) and Brutal strikes(w) whenever up until gank acheived or you need to fall back.
with this build you reach 40% cd reduction without blue so after you have both randuins omen and frozen heart start giving it to the ap carry.
The initial cloth armor plus healing pots is primarily for survival of the first walk through the jungle. usually it is good to use a health pot at blue, first wraiths and first red. cooldown reduction boots as well as the frozen heart and randuins omen will get you hardcapped on cooldown reduction without blue.
This is easily substituted for blue buff, and runes should you want to alter the build, I reccomend speed 5 boots or speed 3 boots if you can cooldown cap through other means. randuins omen is particularly good because due to the immense amount of area of effect that malphite does it can be used directly in conjunction with his ultimate and ground slam(e) spells. For mana regen you can go chalice of harmony instead of thornmail then swap that later if you are giving blue away and have mana issues.
You want to max out your ground slam(e) very soon because it gets your damage bonus from armor to 50%, you get seismic shard(q) strictly to chase down enemies, stealing movement speed, lead with Brutal strikes(w) in all encounters in order to get the attack damage and armor buff, this armor will also add to the damage that ground slam(e) does, which at max level does additional 50% armor value as magic damage. Then ulti in and spam ground slam(e) and Brutal strikes(w), with seismic shard(q) to chase.
In team fights it is extremely important that you ulti only when you can get at minimum three enemies with it. it is often helpful to start the team fight but using malphites ultimate to initiate especially because he is pretty tanky, this strategy works particularly well with guardian angel, just in case you do go down.
This rune set was put together with jungling in mind, the purpose for all of the attack speed is that his Brutal strikes(w) skill causes every basic attack to cleave(do damage) to enemies near his target. this means with attack speed, in a team fight you are hitting multiple enemies faster. It is also very useful when jungling because many of the jungle creeps come in groups and often you will kill them all at the same time because of the splash damage.
You can also substitute the attack speed runes for armor pen to help with ganks, however it will be somewhat detrimental to your jungleing ability.
mana regen is more for late game when you dont have blue ( passing it to the ap carry) however if you want to you can go speed 5 or 3 boots instead of cd reduction, get blue the whole game and get scaling cd reduction glyphs, but I reccomend not doing this because your items will cap your cd reduction no problem, whereas your ap carry might be going all ap and need the extra mana and cd reduction.
When jungling malphite always go flat armor yellows, you need them to do enough damage and live through your first run through the jungle.
Creeping / Jungling
when jungling for the first run through you wanna start blue or wolves, with wolves have someone from top lane help, always always always use ignite on blue right out the gate, then spam ground slam(e) and smite. after level two do not forget to wait ten seconds for your passive 10% helth shield to regen, after level 3 or 4 this is not necessary. lead with your Brutal strikes(w)(armor and attack damage) then use ground slam(e). do not use seismic shard(q) for jungling it wastes a ton of mana even with blue buff.
My preffered path is wolves and blue first. (wolves if you have help, blue if only a leash), then wraiths, red, golems, wolves(they will be back up), then hussle to golems again, they will pop up just before you reach them, then back to wraiths, wolves, golems. until blue is back up.
Pros / Cons
the pro's to this build are that you have more damage, and more armor, you dont however have as much health as some of the other builds. the problem is that if you rush warmogs or atmas impaler, you are sacrificing a ton of gold on non armor items, which fuel your damage in ground slam(e).
The pro's then are, capped cooldown reduction, more armor, more mana, more damage from skills.
the con's being less health, less attack damage (basic attacks)
one of the unique things about this build is that you get a gold producing item (heart of gold) while jungling. this produces a somewhat more consisten stream of gold to fuel your items even if the ganks aren't rolling in. What i often do too is get randuins earlier if im getting lots of ganks in lanes, if not i purchase randuins much later so that my heart of gold will keep some money comming in.
perhaps the most unique thing about this build is that your really quite dangerous as malphite rather than just being the beefy tank with no damage, plus all the armor helps diving towers hurt a lot less.
if you do find yourself in lane, holding for a freind that had to b back, the easiest way to farm on malphite is to position yourself between the enemy melee creeps and spell caster creeps, then using your brutal strikes(w) ability for added armor, then your ground slam ability(e) which does extra damage with said armor. this should hit all the enemy creeps. then you melee the middle melee creep until he is dead, so that your own creeps do not steal last hits, then switch to the middle enemy caster creep, brutal strikes will often get last hits for you, and make sure to cycle in a ground slam(e) if your worried about missing some last hits.
never be last one into the teamfight
when you ultimate in a team fight use it to save an ally or hit at least 3 enemy champs
use brutal strikes(w) before jumping in to get attack damage and armor buff.
while in the midst of the teamfight tag the lowest health enemy champ with seismic shard(q)
so that they cannot escape.
try to hit more than one enemy champ with every ground slam(e), try not to waste cd on single targets in a teamfight.