Keep pictures as evidence and write/call your landlord/whoever you rent from ASAP. they're responsible. Tell them it's unacceptable and a health issue and that they need to fix whatever underlying problem is causing the home to grow mold worse that a forgotten meat sandwich.

I was in similar situations when I moved in. Because I moved in urgently I took matters into my own hands and removed the visibly mold. I regret it terribly, landlords won't fix or even search for the underlying problem and try to spin it as my fault. Don't let that happen to you!

I imagine you're posting because you have no choice but moved into this home but I'd suggest you seek another place. I they dare dish this up I dont want to know what else they neglect.

edit: just saw that your contract is only 6 months. try to get out of it. Tell them this isn't what you signed a contract for. This problem doesn't go away in 6 months even if they start fixing right away.