Function at 0x403f01
Capabilities:
Accept command line arguments
Check os version
Copy file
Delete file
Get common file path
Get file system object information
Set current directory
Set environment variable
Shutdown system
Terminate process

Disassembly:
sub esp, 0x218
push ebx
push ebp
push esi
push edi
xor ebx, ebx
mov edi, str.Error_writing_temporary_file._Make_sure_your_temp_folder_is_valid.
push 0x8001
mov dword [esp + 0x14], ebx
mov ebp, ebx
call dword [sym.imp.KERNEL32.dll_SetErrorMode]
mov esi, dword [sym.imp.KERNEL32.dll_GetVersionExA]
lea eax, [esp + 0x2c]
xorps xmm0, xmm0
mov dword [esp + 0x40], ebx
push eax
movlpd qword [esp + 0xc4], xmm0
mov dword [esp + 0x30], 0x9c
call esi
test eax, eax
jne 0x403f8b
lea eax, [esp + 0x2c]
mov dword [esp + 0x2c], 0x94
push eax
call esi
mov eax, dword [esp + 0x3c]
cmp eax, 2
jne 0x403f92
cmp byte [esp + 0x40], 0x53
mov byte [esp + 0xc6], 4
jne 0x403f7f
movsx ax, byte [esp + 0x4d]
sub ax, 0x30
jmp 0x403fad
xor ecx, ecx
mov word [esp + 0xc0], cx
jmp 0x403f8f
mov eax, dword [esp + 0x3c]
cmp eax, 2
jae 0x403fb5
mov al, byte [esp + 0x41]
mov byte [esp + 0xc6], bl
cmp al, 0x41
jl 0x403fab
cbw
sub ax, 0x40
jmp 0x403fad
xor eax, eax
mov word [esp + 0xc0], ax
cmp dword [esp + 0x30], 0xa
jae 0x403fc7
movzx eax, word [esp + 0x38]
mov dword [esp + 0x38], eax
jmp 0x403fcb
mov eax, dword [esp + 0x38]
mov dword [0x454df8], eax
movzx eax, byte [esp + 0x30]
shl ax, 8
movzx ecx, ax
movzx eax, byte [esp + 0x34]
or ecx, eax
movzx eax, byte [esp + 0xc0]
shl ax, 8
shl ecx, 0x10
movzx eax, ax
or ecx, eax
movzx eax, byte [esp + 0xc6]
or ecx, eax
mov eax, 0x600
mov dword [0x454dfc], ecx
sar ecx, 0x10
cmp cx, ax
je 0x404025
push ebx
call fcn.0040730e
test eax, eax
je 0x404025
push 0xc00
call eax
mov esi, str.UXTHEME
push esi
call fcn.004069bc
push esi
call dword [sym.imp.KERNEL32.dll_lstrlenA]
inc esi
add esi, eax
cmp byte [esi], bl
jne 0x40402a
push 0xc
call fcn.0040730e
push 0xa
call fcn.0040730e
push 8
mov dword [0x450cf0], eax
call fcn.0040730e
test eax, eax
je 0x40406b
push 0x1e
call eax
test eax, eax
je 0x40406b
or byte [0x454dfc], 0x80
call dword [sym.imp.COMCTL32.dll_InitCommonControls]
push ebx
call dword [sym.imp.ole32.dll_OleInitialize]
push ebx
push 0x160
mov dword [0x454d60], eax
lea eax, [esp + 0xd0]
push eax
push ebx
push 0x409b1b
call dword [sym.imp.SHELL32.dll_SHGetFileInfoA]
push str.NSIS_Error
push 0x450d00
call fcn.00407533
call dword [sym.imp.KERNEL32.dll_GetCommandLineA]
push eax
mov ebx, 0x47d000
push ebx
call fcn.00407533
cmp byte [0x47d000], 0x22
mov edx, 0x47d001
mov dword [0x450cf4], 0x400000
sete al
lea eax, [eax*2 + 0x20]
push eax
mov eax, ebx
cmove eax, edx
push eax
call fcn.00406eee
push eax
call dword [sym.imp.USER32.dll_CharNextA]
mov ecx, eax
mov dword [esp + 0x14], ecx
jmp 0x404169
inc ecx
mov dl, byte [ecx]
cmp dl, 0x20
je 0x4040f3
mov byte [esp + 0x18], 0x20
mov bl, dl
cmp dl, 0x22
jne 0x40410e
mov bl, byte [ecx + 1]
mov byte [esp + 0x18], dl
lea eax, [ecx + 1]
cmovne eax, ecx
cmp bl, 0x2f
jne 0x404155
inc eax
cmp byte [eax], 0x53
jne 0x404135
mov cl, byte [eax + 1]
cmp cl, 0x20
je 0x40412b
test cl, cl
jne 0x404135
mov dword [0x454de0], 1
cmp dword [eax], 0x4352434e
jne 0x40414c
mov cl, byte [eax + 4]
cmp cl, 0x20
je 0x404149
test cl, cl
jne 0x40414c
or ebp, 4
cmp dword [eax - 2], 0x3d442f20
je 0x404171
push dword [esp + 0x18]
push eax
call fcn.00406eee
mov ecx, eax
mov dl, byte [ecx]
cmp dl, 0x22
jne 0x40416b
inc ecx
mov dl, byte [ecx]
test dl, dl
jne 0x4040f6
jmp 0x404183
mov byte [eax - 2], 0
add eax, 2
push eax
push 0x47f000
call fcn.00407533
mov esi, dword [sym.imp.KERNEL32.dll_GetTempPathA]
mov ebx, 0x487000
push ebx
push 0x2000
call esi
call fcn.0040445d
test eax, eax
jne 0x4041f5
push 0x1ffb
push ebx
call dword [sym.imp.KERNEL32.dll_GetWindowsDirectoryA]
push str.Temp
push ebx
call sub.KERNEL32.dll_lstrcatA
call fcn.0040445d
test eax, eax
jne 0x4041f5
push ebx
push 0x1ffc
call esi
push 0x409b30
push ebx
call sub.KERNEL32.dll_lstrcatA
mov esi, dword [sym.imp.KERNEL32.dll_SetEnvironmentVariableA]
push ebx
push str.TEMP
call esi
push ebx
push 0x409b3c
call esi
call fcn.0040445d
test eax, eax
je 0x404395
mov ebx, dword [sym.imp.KERNEL32.dll_DeleteFileA]
push 0x485000
call ebx
push ebp
call fcn.00403a83
mov edi, eax
test edi, edi
jne 0x404395
cmp dword [0x454d0c], eax
je 0x40426c
push eax
mov ebp, 0x47d000
push ebp
call fcn.00406eee
mov esi, eax
jmp 0x404233
cmp dword [esi], 0x3d3f5f20
je 0x404237
dec esi
cmp esi, ebp
jae 0x40422a
mov edi, str.Error_launching_installer
cmp esi, ebp
jb 0x404286
mov byte [esi], 0
add esi, 4
push esi
call fcn.00406f2b
test eax, eax
je 0x404395
push esi
push 0x47f000
call fcn.00407533
push esi
push 0x481000
call fcn.00407533
xor edi, edi
or dword [0x454dec], 0xffffffff
call fcn.004061e6
push 1
mov ebx, eax
call fcn.00406fd4
jmp 0x404399
call fcn.00406c5e
push str.nsu
mov ebp, 0x487000
mov esi, eax
push ebp
call sub.KERNEL32.dll_lstrcatA
test esi, esi
je 0x4042ac
push 0x409b48
push ebp
call sub.KERNEL32.dll_lstrcatA
push str..tmp
push ebp
call sub.KERNEL32.dll_lstrcatA
push 0x483000
push ebp
call dword [sym.imp.KERNEL32.dll_lstrcmpiA]
test eax, eax
je 0x404395
push ebp
test esi, esi
je 0x4042d7
call fcn.0040663a
jmp 0x4042dc
call fcn.0040661a
push ebp
call dword [sym.imp.KERNEL32.dll_SetCurrentDirectoryA]
cmp byte [0x47f000], 0
jne 0x4042fb
push 0x483000
push 0x47f000
call fcn.00407533
push dword [esp + 0x14]
push section..ndata
call fcn.00407533
push 0x41
pop eax
push 0x1a
mov word [0x457000], ax
pop esi
mov eax, dword [0x454d18]
push dword [eax + 0x120]
push 0x433d18
call fcn.004066b6
push 0x433d18
call ebx
test edi, edi
je 0x404383
push 1
push 0x433d18
push 0x48b000
call dword [sym.imp.KERNEL32.dll_CopyFileA]
test eax, eax
je 0x404383
push 0
push 0x433d18
call fcn.00406a57
mov eax, dword [0x454d18]
push dword [eax + 0x124]
push 0x433d18
call fcn.004066b6
push 0x433d18
call fcn.0040708d
test eax, eax
je 0x404383
push eax
call dword [sym.imp.KERNEL32.dll_CloseHandle]
xor edi, edi
inc byte [0x457000]
sub esi, 1
jne 0x404315
push esi
push ebp
call fcn.00406a57
mov ebx, dword [esp + 0x10]
call fcn.00403ed7
call dword [sym.imp.ole32.dll_OleUninitialize]
test edi, edi
je 0x4043bb
push 0x200010
push edi
call fcn.004074c1
push 2
call dword [sym.imp.KERNEL32.dll_ExitProcess]
cmp dword [0x454dd4], 0
je 0x404449
lea eax, [esp + 0x14]
push eax
push 0x28
call dword [sym.imp.KERNEL32.dll_GetCurrentProcess]
push eax
call dword [sym.imp.ADVAPI32.dll_OpenProcessToken]
test eax, eax
je 0x404417
lea eax, [esp + 0x20]
push eax
push str.SeShutdownPrivilege
push 0
call dword [sym.imp.ADVAPI32.dll_LookupPrivilegeValueA]
xor ecx, ecx
mov dword [esp + 0x1c], 1
push ecx
push ecx
push ecx
lea eax, [esp + 0x28]
mov dword [esp + 0x34], 2
push eax
push ecx
push dword [esp + 0x28]
call dword [sym.imp.ADVAPI32.dll_AdjustTokenPrivileges]
push 4
call fcn.0040730e
mov esi, 0x80040002
test eax, eax
je 0x404435
push esi
push 0x25
xor ecx, ecx
push ecx
push ecx
push ecx
call eax
test eax, eax
je 0x404442
push esi
push 2
call dword [sym.imp.USER32.dll_ExitWindowsEx]
test eax, eax
jne 0x404449
push 9
call fcn.0040153c
cmp dword [0x454dec], 0xffffffff
cmovne ebx, dword [0x454dec]
push ebx
jmp 0x4043b5