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// This rule has been modified by @mmorenog @yarules to fix some errors
import "pe"
rule RomeoFoxtrot
{
meta:
copyright = "2015 Novetta Solutions"
author = "Novetta Threat Research & Interdiction Group - trig@novetta.com"
Source = "dropped.bin"
Source_relativeCalls = "635bebe95671336865f8a546f06bf67ab836ea35795581d8a473ef2cd5ff4a7f"
strings:
/*
C7 44 24 08 01 00 00 00 mov [esp+128h+argp], 1
8B 8C 24 30 01 00 00 mov ecx, dword ptr [esp+128h+wPort]
C7 44 24 04 00 00 20 03 mov dword ptr [esp+128h+optval], 3200000h
51 push ecx ; hostshort
89 44 24 1C mov dword ptr [esp+12Ch+name.sin_addr.S_un], eax
FF 15 8C 01 FF 7E call ds:htons
6A 06 push 6 ; protocol
6A 01 push 1 ; type
6A 02 push 2 ; af
66 89 44 24 22 mov [esp+134h+name.sin_port], ax
66 C7 44 24 20 02 00 mov [esp+134h+name.sin_family], 2
FF 15 84 01 FF 7E call ds:socket <--- this could be a relative call in some variants
83 F8 FF cmp eax, 0FFFFFFFFh
89 46 04 mov [esi+4], eax
0F 84 AD 00 00 00 jz loc_7EFE4C63
57 push edi
8B 3D 88 01 FF 7E mov edi, ds:setsockopt <---- this line is missing when relative calls are used
8D 54 24 08 lea edx, [esp+12Ch+optval]
6A 04 push 4 ; optlen
52 push edx ; optval
68 02 10 00 00 push 1002h ; optname
68 FF FF 00 00 push 0FFFFh ; level
50 push eax ; s
FF D7 call edi ; setsockopt <--- this could be a relative call in some variants
8B 4E 04 mov ecx, [esi+4]
8D 44 24 08 lea eax, [esp+12Ch+optval]
6A 04 push 4 ; optlen
50 push eax ; optval
68 01 10 00 00 push 1001h ; optname
68 FF FF 00 00 push 0FFFFh ; level
51 push ecx ; s
FF D7 call edi ; setsockopt <--- this could be a relative call in some variants
*/
//$connect = {C7 [3] 01 00 00 00 8B [6] C7 [3] 00 00 20 03 5? 89 [3] (FF 15 [4] | E8 [4]) 6A 06 6A 01 6A 02 66 [4] 66 [4] 02 00 (FF 15 [4] | E8 [4]) 83 F8 FF 89 [2] 0F 84 [4] [0-7] 8D [3] 6A 04 5? 68 02 10 00 00 68 FF FF 00 00 5? (FF D? | E8 [4]) 8B [2] 8D [3] 6A 04 5? 68 01 10 00 00 68 FF FF 00 00 5? (FF D? | E8 [4])}
$connect = {C7 [3] 01 00 00 00 8B [6] C7 [3] 00 00 20 03 5? 89 [3] FF 15 [4] 6A 06 6A 01 6A 02 66 [4] 66 [4] 02 00 FF 15 E8 [4] 83 F8 FF 89 [2] 0F 84 [4] [0-7] 8D [3] 6A 04 5? 68 02 10 00 00 68 FF FF 00 00 5? FF D? 8B [2] 8D [3] 6A 04 5? 68 01 10 00 00 68 FF FF 00 00 5? FF D?}
$response = "RESPONSE 200 OK!!!"
condition:
($challenge and $response) or
$connect in ((pe.sections[pe.section_index(".text")].raw_data_offset)..(pe.sections[pe.section_index(".text")].raw_data_offset + pe.sections[pe.section_index(".text")].raw_data_size))
}