jthuraisamy

### Keybase proof

I hereby claim:

  * I am jthuraisamy on github.
  * I am jthuraisamy (https://keybase.io/jthuraisamy) on keybase.
  * I have a public key whose fingerprint is 3CC0 1B4C 2920 F44E 8973  2DFD 764F 2E48 2337 A611

To claim this, I am signing this object:

jthuraisamy

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# References:
# 1. https://pentestlab.blog/2017/12/13/smb-share-scf-file-attacks/
# 2. https://room362.com/post/2016/smb-http-auth-capture-via-scf/

from argparse import ArgumentParser
from configparser import RawConfigParser

jthuraisamy

Usage

This script generates a payload for use with Responder.

1. Generate a payload with main.py
2. Copy and paste the one-liner output into the WPADScript field of Responder.conf.

test@test:~$ python3 main.py --help
usage: main.py [-h] [-o OUT] cmd

jthuraisamy

PyExZ3 Example with HackSysExtremeVulnerableDriver

TL;DR: Using symbolic execution to recover driver IOCTL codes that are computed at runtime.

The goal here is to find valid IOCTL codes for the HackSysExtremeVulnerableDriver by analyzing the binary. The control flow varies between the binary and source due to compiler optimizations. This results in a situation where only a few IOCTL codes in the assembly are represented as a constant with the remaining being computed at runtime.

The code in hevd_ioctl.py is a approximation of the control flow of the compiled IrpDeviceIoCtlHandler function. The effects of the compiler optimization are more pronounced when comparing this code to the original C function. To comply with requirements of the PyExZ3 module, the target function is named after the script's filename, and the `ex

jthuraisamy

"""
IDAPython Script to highlight function calls.
Re-implemented by jthuraisamy (not the original author).

Install to %IDADIR%\plugins\highlight_calls.py.

Run by pressing Ctrl+Alt+H or go to Options -> Highlight Call Instructions.
"""

class HighlightHandler(idaapi.action_handler_t):

jthuraisamy

Windows Toolkit

Binary

Native Binaries

• IDA Pro

IDA Plugins	Preferred	Neutral	Unreviewed

jthuraisamy

GospelRoom: Data Storage in UEFI NVRAM Variables

Behaviour

Persist data in UEFI NVRAM variables.

Benefits

1. Stealthy way to store secrets and other data in UEFI.
2. Will survive a reimaging of the operating system.

jthuraisamy

.code

NtCreateFile PROC
	mov rax, gs:[60h]
NtCreateFile_Check_X_X_XXXX:        ; Check major version.
	cmp dword ptr [rax+118h], 5
	je  NtCreateFile_SystemCall_5_X_XXXX
	cmp dword ptr [rax+118h], 6
	je  NtCreateFile_Check_6_X_XXXX
	cmp dword ptr [rax+118h], 10

jthuraisamy

.code

NtAcceptConnectPort PROC
    mov rax, gs:[60h]                             ; Load PEB into RAX.
NtAcceptConnectPort_Check_X_X_XXXX:               ; Check major version.
    cmp dword ptr [rax+118h], 5
    je  NtAcceptConnectPort_SystemCall_5_X_XXXX
    cmp dword ptr [rax+118h], 6
    je  NtAcceptConnectPort_Check_6_X_XXXX
    cmp dword ptr [rax+118h], 10

jthuraisamy

import os.path
import pefile

print('#pragma once')

target_dll = r'target.dll'
pe = pefile.PE(target_dll)
for export in pe.DIRECTORY_ENTRY_EXPORT.symbols:
    if export.name:
        name = export.name.decode()