Here are some weapons and items that can be found in the Midnight Society ARG:

Bloody Bat
Suppressed .45
Modified Scar-H
Modified AK-Variant
Integrated Harness
Tactical Knife
Modified G36c
Broken Scar-H
V7 Sniper Rifle
Suppressed G36c
HSD Frag Grenade
X-1 Assault Rifle
6-IR Grenade Launcher
Insured M-99 Assault Rifle
Insured Tax-X Machine Pistol
Insured Modified M249 SAW

VisorCortex Nikolai
VisorCortex LordsofKarma
VisorCortex Moonlight
VisorCortex AngelxThanatos
VisorCortex Bacon
Insured VisorCortex Solid
Insured VisorCortex RatBoy

Gas Mask
7.62 Ammo
Med Kit
.45 Rounds
.45 Ammo
Lock 2 Codex
Lock 4 Codex
Lock 3 Codex
Lock 1 Codex
Bloody Note