Function at 0x403440
Capabilities:
Allocate or change rwx memory
Check if file exists
Execute shellcode via indirect call
Get file attributes
Get file size
Read file on windows

Disassembly:
push ebp
mov ebp, esp
push 0xffffffffffffffff
push 0x43ee83
mov eax, dword fs:[0]
push eax
sub esp, 0x80
mov eax, dword [0x450670]
xor eax, ebp
mov dword [ebp - 0x14], eax
push ebx
push esi
push edi
push eax
lea eax, [ebp - 0xc]
mov dword fs:[0], eax
mov dword [ebp - 0x10], esp
call fcn.00403290
lea eax, [ebp - 0x30]
xor ebx, ebx
push eax
mov dword [ebp - 4], ebx
call fcn.00401b20
add esp, 4
mov byte [ebp - 4], 1
mov eax, dword [ebp - 0x2c]
mov edi, 0x10
cmp dword [ebp - 0x18], edi
jae 0x40349b
lea eax, [ebp - 0x2c]
push eax
call dword [sym.imp.KERNEL32.dll_GetFileAttributesA]
cmp eax, 0xffffffff
jne 0x403649
lea ecx, [ebp - 0x4c]
call fcn.004018e0
lea edx, [ebp - 0x30]
lea ecx, [ebp - 0x4c]
mov byte [ebp - 4], 2
call fcn.00402160
test al, al
jne 0x40352b
push ebx
push 0x446278
push 0x446280
push ebx
call dword [sym.imp.USER32.dll_MessageBoxA]
cmp dword [ebp - 0x34], edi
jb 0x4034e9
mov ecx, dword [ebp - 0x48]
push ecx
call fcn.00408e23
add esp, 4
mov dword [ebp - 0x34], 0xf
mov dword [ebp - 0x38], ebx
mov byte [ebp - 0x48], 0
cmp dword [ebp - 0x18], edi
jb 0x403508
mov edx, dword [ebp - 0x2c]
push edx
call fcn.00408e23
add esp, 4
mov eax, 1
mov ecx, dword [ebp - 0xc]
mov dword fs:[0], ecx
pop ecx
pop edi
pop esi
pop ebx
mov ecx, dword [ebp - 0x14]
xor ecx, ebp
call fcn.00424daa
mov esp, ebp
pop ebp
ret 0x10
push 0x28
mov esi, 0xf
push str.4d5c02154308c79a559fba5592167e85b20ec542
lea ecx, [ebp - 0x84]
mov dword [ebp - 0x6c], esi
mov dword [ebp - 0x70], ebx
mov byte [ebp - 0x80], 0
call fcn.00405000
mov dword [ebp - 0x50], esi
mov dword [ebp - 0x54], ebx
mov byte [ebp - 0x64], 0
lea eax, [ebp - 0x68]
push eax
lea ecx, [ebp - 0x30]
mov byte [ebp - 4], 4
call fcn.00401d10
add esp, 4
test al, al
jne 0x4035e2
push ebx
push 0x446278
push 0x4462bc
push ebx
call dword [sym.imp.USER32.dll_MessageBoxA]
cmp dword [ebp - 0x50], edi
jb 0x403590
mov ecx, dword [ebp - 0x64]
push ecx
call fcn.00408e23
add esp, 4
mov dword [ebp - 0x50], esi
mov dword [ebp - 0x54], ebx
mov byte [ebp - 0x64], 0
cmp dword [ebp - 0x6c], edi
jb 0x4035ab
mov edx, dword [ebp - 0x80]
push edx
call fcn.00408e23
add esp, 4
mov dword [ebp - 0x6c], esi
mov dword [ebp - 0x70], ebx
mov byte [ebp - 0x80], 0
cmp dword [ebp - 0x34], edi
jb 0x4035c6
mov eax, dword [ebp - 0x48]
push eax
call fcn.00408e23
add esp, 4
mov dword [ebp - 0x34], esi
mov dword [ebp - 0x38], ebx
mov byte [ebp - 0x48], 0
cmp dword [ebp - 0x18], edi
jb 0x403508
mov ecx, dword [ebp - 0x2c]
push ecx
jmp 0x403500
lea eax, [ebp - 0x84]
lea edx, [ebp - 0x68]
call fcn.00407940
test al, al
je 0x40362e
push ebx
push 0x446278
push 0x4462d0
push ebx
call dword [sym.imp.USER32.dll_MessageBoxA]
lea ecx, [ebp - 0x68]
call fcn.004038e0
lea ecx, [ebp - 0x84]
call fcn.004038e0
lea ecx, [ebp - 0x4c]
call fcn.004038e0
lea ecx, [ebp - 0x30]
call fcn.004038e0
jmp 0x403508
lea ecx, [ebp - 0x68]
call fcn.004038e0
lea ecx, [ebp - 0x84]
call fcn.004038e0
lea ecx, [ebp - 0x4c]
call fcn.004038e0
mov eax, dword [ebp - 0x2c]
cmp dword [ebp - 0x18], edi
jae 0x403654
lea eax, [ebp - 0x2c]
push ebx
push 0x80
push 3
push ebx
push 1
push SysReAllocString
push eax
call dword [sym.imp.KERNEL32.dll_CreateFileA]
mov esi, eax
push ebx
cmp esi, 0xffffffff
jne 0x403689
push 0x446278
push 0x4462f0
push ebx
call dword [sym.imp.USER32.dll_MessageBoxA]
jmp 0x4034f7
push esi
call dword [sym.imp.KERNEL32.dll_GetFileSize]
mov edi, eax
cmp edi, 0xffffffff
jne 0x4036c3
push ebx
push 0x446278
push 0x446300
push ebx
call dword [sym.imp.USER32.dll_MessageBoxA]
push esi
call dword [sym.imp.KERNEL32.dll_CloseHandle]
cmp dword [ebp - 0x18], 0x10
jb 0x403508
mov eax, dword [ebp - 0x2c]
push eax
jmp 0x403500
push 0x40
push 0x1000
push edi
push ebx
call dword [sym.imp.KERNEL32.dll_VirtualAlloc]
mov ebx, eax
mov dword [ebp - 0x8c], ebx
push 0
test ebx, ebx
jne 0x403705
push 0x446278
push 0x446314
push eax
call dword [sym.imp.USER32.dll_MessageBoxA]
push esi
call dword [sym.imp.KERNEL32.dll_CloseHandle]
lea ecx, [ebp - 0x30]
call fcn.004038e0
jmp 0x403508
lea ecx, [ebp - 0x88]
push ecx
push edi
push ebx
push esi
call dword [sym.imp.KERNEL32.dll_ReadFile]
test eax, eax
je 0x403755
cmp dword [ebp - 0x88], edi
jne 0x403755
push esi
call dword [sym.imp.KERNEL32.dll_CloseHandle]
pushal
mov eax, dword [ebp - 0x8c]
call eax
popal
mov edx, dword [ebp - 0x8c]
push 0x8000
push 0
push edx
call dword [sym.imp.KERNEL32.dll_VirtualFree]
lea ecx, [ebp - 0x30]
call fcn.004038e0
xor eax, eax
jmp 0x40350d
push 0
push 0x446278
push 0x446324
push 0
call dword [sym.imp.USER32.dll_MessageBoxA]
push 0x8000
push 0
push ebx
call dword [sym.imp.KERNEL32.dll_VirtualFree]
push esi
call dword [sym.imp.KERNEL32.dll_CloseHandle]
lea ecx, [ebp - 0x30]
call fcn.004038e0
jmp 0x403508