Function at 0x83f9b0
Capabilities:
Get file size
Read file on windows
Write file on windows

Disassembly:
push 0xffffffffffffffff
push 0x85c2f8
mov eax, dword fs:[0]
push eax
mov dword fs:[0], esp
sub esp, 0x24
push ebx
push esi
push edi
call dword [sym.imp.KERNEL32.dll_GetTickCount]
mov cl, byte [esp + 0x40]
mov ebx, eax
mov al, byte [esp + 0x40]
xor esi, esi
mov byte [esp + 0x21], cl
lea ecx, [esp + 0x20]
and ebx, 0x3f
mov dword [esp + 0x18], esi
mov dword [esp + 0x1c], esi
mov byte [esp + 0x20], al
mov byte [esp + 0x28], 0
call fcn.00840510
mov edi, dword [esp + 0x40]
lea edx, [esp + 0x18]
push edx
push edi
mov dword [esp + 0x40], esi
call fcn.0083f8f0
add esp, 8
test al, al
je 0x83fbe2
shl ebx, 0xc
mov eax, ebx
push ebp
shr eax, 0xc
shl eax, 0xc
cmp eax, ebx
je 0x83fa33
xor bl, bl
jmp 0x83fb60
push esi
push esi
push 3
push esi
push 1
push SysReAllocString
push edi
call dword [sym.imp.KERNEL32.dll_CreateFileW]
mov ebp, eax
cmp ebp, 0xffffffff
jne 0x83fa54
xor bl, bl
jmp 0x83fb60
push esi
push ebp
call dword [sym.imp.KERNEL32.dll_GetFileSize]
cmp eax, 0x1000
mov dword [esp + 0x14], eax
jae 0x83fa6e
xor bl, bl
jmp 0x83fb60
lea edi, [eax + ebx]
push edi
mov dword [esp + 0x1c], edi
call fcn.0084c1d3
mov ecx, edi
mov esi, eax
mov edx, ecx
xor eax, eax
mov edi, esi
add esp, 4
shr ecx, 2
rep stosd dword es:[edi], eax
mov ecx, edx
push 0
and ecx, 3
rep stosb byte es:[edi], al
mov edi, dword [sym.imp.KERNEL32.dll_ReadFile]
lea eax, [esp + 0x14]
push eax
push 0x1000
push esi
push ebp
call edi
mov edx, dword [esp + 0x14]
lea ecx, [esp + 0x10]
push 0
add edx, 0xfffff000
push ecx
lea eax, [esi + ebx + 0x1000]
push edx
push eax
push ebp
call edi
push ebp
mov ebp, dword [sym.imp.KERNEL32.dll_CloseHandle]
call ebp
lea ecx, [esp + 0x14]
push ecx
lea ecx, [esp + 0x28]
call fcn.0083fd60
mov eax, dword [esp + 0x14]
mov ecx, dword [esp + 0x28]
cmp eax, ecx
mov dword [esp + 0x44], eax
je 0x83fb17
mov eax, dword [eax + 0xc]
cmp eax, 0x1000
jb 0x83fafa
add eax, ebx
mov edx, dword [eax + esi]
lea ecx, [esp + 0x44]
add edx, ebx
mov dword [eax + esi], edx
call fcn.00840080
mov eax, dword [esp + 0x44]
mov ecx, dword [esp + 0x28]
cmp eax, ecx
jne 0x83faee
mov edx, dword [esp + 0x48]
push 0
push 0
push 2
push 0
push 0
push 0x40000000
push edx
call dword [sym.imp.KERNEL32.dll_CreateFileW]
mov edi, eax
cmp edi, 0xffffffff
jne 0x83fb3c
xor bl, bl
jmp 0x83fb5e
mov ecx, dword [esp + 0x18]
lea eax, [esp + 0x10]
push 0
push eax
push ecx
push esi
push edi
call dword [sym.imp.KERNEL32.dll_WriteFile]
push edi
call ebp
push esi
call fcn.0084c1c8
add esp, 4
mov bl, 1
xor esi, esi
mov eax, dword [esp + 0x28]
lea edx, [esp + 0x44]
push eax
mov dword [esp + 0x40], 0xffffffff
mov ecx, dword [eax]
push ecx
push edx
lea ecx, [esp + 0x30]
call fcn.0083ffb0
mov eax, dword [esp + 0x28]
push eax
call fcn.0084c1c8
add esp, 4
lea ecx, [esp + 0x44]
mov dword [esp + 0x28], esi
mov dword [esp + 0x30], esi
xor edi, edi
call fcn.0085bce0
mov eax, dword [0x866750]
pop ebp
dec eax
mov dword [0x866750], eax
jne 0x83fbb8
mov edi, dword [0x86674c]
mov dword [0x86674c], esi
lea ecx, [esp + 0x40]
call fcn.0085bd7c
cmp edi, esi
je 0x83fbce
push edi
call fcn.0084c1c8
add esp, 4
pop edi
mov al, bl
pop esi
pop ebx
mov ecx, dword [esp + 0x24]
mov dword fs:[0], ecx
add esp, 0x30
ret
mov eax, dword [esp + 0x24]
mov dword [esp + 0x38], 0xffffffff
push eax
mov ecx, dword [eax]
push ecx
lea ecx, [esp + 0x48]
push ecx
lea ecx, [esp + 0x2c]
call fcn.0083ffb0
mov edx, dword [esp + 0x24]
push edx
call fcn.0084c1c8
add esp, 4
lea ecx, [esp + 0x44]
mov dword [esp + 0x24], esi
mov dword [esp + 0x2c], esi
xor edi, edi
call fcn.0085bce0
mov eax, dword [0x866750]
dec eax
mov dword [0x866750], eax
jne 0x83fc39
mov edi, dword [0x86674c]
mov dword [0x86674c], esi
lea ecx, [esp + 0x44]
call fcn.0085bd7c
cmp edi, esi
je 0x83fc4f
push edi
call fcn.0084c1c8
add esp, 4
mov ecx, dword [esp + 0x30]
pop edi
pop esi
xor al, al
pop ebx
mov dword fs:[0], ecx
add esp, 0x30
ret