radare2 Scripts

Summary

A 'collection' of scripts to be used with radare2.

• r2_bin_carver.py - A script used to carve files from memory dumps.
• r2_hash_func_decoder.py - A script used to decode hashed functions, commonly found in shellcode.

Scripts

Binary Carver

This script will carve files from memory dumps (MDMP), given an offset and a size. In addition to carving it also supports basic patching for carved PE files. At the time of writing this will patch the offsets within the PE sections headers.

Requirements

pip install r2pipe

Sample output with default arguments:

Examples

$ python2 ./r2_bin_carver.py ./memory.dmp 0x04af0000 0x2f000
[+] Carving to ./memory.dmp.0x04af0000

Sample output for binary carving using magic checking and patching:

$ python2 ./r2_bin_carver.py -p -b MZ ./memory.dmp 0x04af0000 0x2f000
[+] Checking for magic: MZ - 4d5a
[+] Magic found, carving...
[+] Carving to ./memory.dmp.0x04af0000
[+] Patching...
[+] Found 3 sections to patch
[+] Patching Section 0.
  Setting VirtualSize to 0x1fb0
  Setting PointerToRawData to 0x1000
[+] Patching Section 1.
  Setting VirtualSize to 0x5b7f
  Setting PointerToRawData to 0x3000
[+] Patching Section 2.
  Setting VirtualSize to 0x254d2
  Setting PointerToRawData to 0x9000
[+] Pathing done

Hashed Function Decoder

This script will decode function hashes via lookup using a pre-generated database of hashes. It will handle the generation, searching and analysis for the supported hashing techniques.

Requirements

pip install pefile r2pipe sqlite3

Supported Techniques

The currently supported hashing techniques.

$ python2 ./r2_hash_func_decoder.py -l
Suported Hashing Techniques:
- doublepulsar
- metasploit

Generating the Database

This will create hashes for all exported functions of a DLL or EXE, for all supported hashing techniques.

$ python2 ./r2_hash_func_decoder.py -g ntdll.dll
Generating Hashes:
Processing ./ntdll.dll...

Searching the Database

Manually searching the database for a given hash.

$ python2 ./r2_hash_func_decoder.py -s 0x6f721347
Searching for 0x6F721347...
- metasploit: ntdll.dll!RtlExitUserThread()

Auto analysis in radare2

This will search all defined funtions within radare2 for hashes to decode for a given technique.

$ r2 shellcode
> af @ 0x0
> afl
0x00000000   31 931          fcn.00000000
> #!pipe python2 ./r2_hash_func_decoder.py -a doublepulsar
Analysing:
Function: fcn.00000000 0x0 931
|_ 0x0000001f   movabs rcx, 0x3e1481df    ntoskrnl.exe!PsLookupProcessByProcessId
|_ 0x0000003e   movabs rcx, 0xa0031eba    ntoskrnl.exe!PsGetProcessImageFileName
|_ 0x0000005d   movabs rcx, 0xfffffffff9e70684    ntoskrnl.exe!KeStackAttachProcess
|_ 0x0000007c   movabs rcx, 0x15ebfe4f    ntoskrnl.exe!PsGetProcessPeb
|_ 0x0000009b   movabs rcx, 0xa4ac30f9    ntoskrnl.exe!KeUnstackDetachProcess
|_ 0x000000ba   movabs rcx, 0xecd0beca    ntoskrnl.exe!ObfDereferenceObject
|_ 0x000000d9   movabs rcx, 0xffffffff5d9fb8ae    ntdll.dll!ZwAllocateVirtualMemory
|_ 0x000000f8   movabs rcx, 0xffffffffe3690194    ntoskrnl.exe!ExAllocatePool
|_ 0x00000117   movabs rcx, 0xffffffffb80010f6    ntoskrnl.exe!KeInitializeApc
|_ 0x00000136   movabs rcx, 0xffffffffd25fd6ca    ntoskrnl.exe!KeInsertQueueApc
|_ 0x00000155   movabs rcx, 0x1124a879    ntoskrnl.exe!KeGetCurrentThread
|_ 0x00000174   movabs rcx, 0x4f90c637    ntoskrnl.exe!PsGetCurrentProcess
|_ 0x00000193   movabs rcx, 0x10fee76c    ntoskrnl.exe!PsGetThreadTeb

In addition to the above it will add comments to the appropriate lines:

[snip]
           0x00000017      e8bc060000     call 0x6d8                  ;[1]
│           0x0000001c      4889c3         mov rbx, rax
│           0x0000001f      48b9df81143e.  movabs rcx, 0x3e1481df      ; ntoskrnl.exe!PsLookupProcessByProcessId
│           0x00000029      e826050000     call 0x554                  ;[2]
│           0x0000002e      4885c0         test rax, rax
│       ┌─< 0x00000031      0f8455030000   je 0x38c                    ;[3]
│       │   0x00000037      4889059c0700.  mov qword [0x000007da], rax ; [0x7da:8]=0
│       │   0x0000003e      48b9ba1e03a0.  movabs rcx, 0xa0031eba      ; ntoskrnl.exe!PsGetProcessImageFileName
│       │   0x00000048      e807050000     call 0x554                  ;[2]
│       │   0x0000004d      4885c0         test rax, rax
│      ┌──< 0x00000050      0f8436030000   je 0x38c                    ;[3]
│      ││   0x00000056      488905850700.  mov qword [0x000007e2], rax ; [0x7e2:8]=0
│      ││   0x0000005d      48b98406e7f9.  movabs rcx, 0xfffffffff9e70684 ; ntoskrnl.exe!KeStackAttachProcess
│      ││   0x00000067      e8e8040000     call 0x554                  ;[2]
[snip]