Didier Stevens

Sunday 9 July 2017

Video: mimikatz & minesweeper

Filed under: Entertainment,Hacking — Didier Stevens @ 16:07

@gentilkiwi‘s mimikatz has a minesweeper module with command infos. This command will show you where the mines are in minesweeper.

Saturday 8 July 2017

Video: mimikatz & !bsod

Filed under: Entertainment,Hacking — Didier Stevens @ 21:53

After the mimikatz !bsod blogpost, here’s the video:

Friday 7 July 2017

Quickpost: mimikatz !bsod

Filed under: Entertainment,Hacking,Quickpost — Didier Stevens @ 20:31

I’m going through the mimikatz source code and I’m finding all kind of gems :-).

Here is one of them, but be careful, do this only on a machine were you won’t mind losing data, because this will crash the machine.

There’s a mimikatz driver command to initiate a Blue Screen of Death: !bsod

Here I’m using mimikatz as administrator on a Windows 7 machine (because I’m not a fan of the new BSOD introduced with Windows 8):

It’s a MANUALLY_INITIATED_CRASH (STOP 0x000000E2).


Quickpost info


Thursday 6 April 2017

Quickpost: Using My Bash Bunny To “Snag Creds From A Locked Machine”

Filed under: Bash Bunny,Entertainment,Hacking,Hardware,Quickpost — Didier Stevens @ 23:22

FYI: This is nothing new, I’m just documenting how I configured and used my new Bash Bunny for “SNAGGING CREDS FROM LOCKED MACHINES” as Mubix explained.

After setting up my Bash Bunny, I used it on a locked Windows 10 machine to get netNTLMv2 hashes, here is the video:

 

After collecting the hashes, I can recover them from the Bash Bunny:

I put my Bash Bunny into arming mode: put the switch in position 3 (switch position closest to the USB connector). I insert my Bash Bunny in my Windows machine. The removable storage on the Bash Bunny gets assigned drive letter D: on my machine.

Inside folder D:\loot\quickcreds there are folders created each time I use this payload on a machine. Here is the content for the Windows 10 machine I collected hashes from (DESKTOP-DEMO):

File Proxy-Auth-NTLMv2-172.16.64.10.txt contains the hashes:

These can be cracked, for example with John The Ripper:

Here is what I did to setup my Bash Bunny after unboxing it:

First I updated the payloads on my Bash Bunny from the GitHub repository.

I put my Bash Bunny into arming mode: put the switch in position 3 (switch position closest to the USB connector). I insert my Bash Bunny in my Windows machine. The removable storage on the Bash Bunny gets assigned drive letter D: on my machine.

I copy the content of the GitHub repository payloads folder to the payloads folder on the Bash Bunny: d:\payloads\ (overwriting existing files).

To install the tools: I copy D:\payloads\library\tools_installer\ to D:\payloads\switch1\ (overwriting existing files).

I eject the Bash Bunny, put the switch in position 1 (payload 1, switch position closest to the LED). I insert the Bash Bunny in my Windows machine, and wait for a white solid LED: this takes about 10 seconds.

I eject the Bash Bunny, put the switch in position 3 and re-insert it into my Windows machine.

Then I set the QuickCreds payload (responder) as payload 2 on my Bash Bunny: copy D:\payloads\library\QuickCreds\ to D:\payloads\switch2\ (overwriting existing files).

I eject the Bash Bunny, put the switch in position 2 (payload 2, switch position in the middle) and insert it into my test Windows machine. After some time, the Bash Bunny displays a green LED, indicating that hashes were collected.


Quickpost info


Thursday 21 August 2014

A Return: The Puzzle

Filed under: Encryption,Entertainment,Hacking,Puzzle — Didier Stevens @ 19:19

It’s been some time that I posted a puzzle. So here is a new little puzzle.

What is special about this file?

20140821- 211452

Tuesday 19 June 2012

_nomap, _nomap, _nomap, …

Filed under: Entertainment,My Software,WiFi — Didier Stevens @ 20:50

About three years ago I released a Python program to send out WiFi beacon frames with an AirPCap adapter. During my last holiday, I took some time to add a new feature to apc-b.py: option nomap.

When you start apc-b.py with option nomap, it first listens for 60 seconds and records all ESSIDs in finds in beacon frames. Then it starts to broadcast beacon frames for these ESSIDs, but with string _nomap appended to each ESSID.

apc-b_v0_2_0.zip (https)
MD5: 849DE418A1F325B9DC133DBE2E7CC501
SHA256: C3F28DCEFE6FF747780E384E49BB4D373BC983518C592E1BB18E8455F78E7F95

Tuesday 8 May 2012

Why Isn’t my PoC Launching calc.exe?

Filed under: Entertainment,Hacking,My Software,Nonsense — Didier Stevens @ 11:17

I quickly developed a dll that kills calc.exe when started from anything else than explorer.exe.

This way, you can mess with all those PoCs that launch calc.exe 😉

nocalcpoc_V0_0_0_1.zip (https)
MD5: 05798543571B45E19536181DC7346330
SHA256: ED0FEDC6096420F6F09F4980A1CE36F7C4BC0A8C9191F4DFC27FA4C77D547976

Saturday 24 December 2011

Happy New Router

Filed under: Entertainment,Hacking,Networking — Didier Stevens @ 0:00

Wednesday 30 December 2009

Detecting EICAR With a .NET Micro-controller

Filed under: .NET,Entertainment,Hardware — Didier Stevens @ 22:07

I’ve been playing with a .NET Micro Framework micro-controller: the USBizi. A few of its interesting characteristics are that you program it in C# with Visual Studio and that in-circuit debugging (including single-stepping) is supported.

The .NET Micro Framework has no assemblies to support USB in host mode (only guest mode), but the USBizi comes with assemblies for host mode providing support for removable drives like USB sticks. To illustrate this feature, I wrote a program to scan the files on a USB stick for the EICAR test file and replace the content with a message appropriate for the time of the year.

Some ideas I’ve for this device: program it as a hardware keylogger, a hardware password vault, …

using System.Threading;
using System;
using System.IO;
using Microsoft.SPOT.Hardware;
using Microsoft.SPOT;
using Microsoft.SPOT.IO;
using GHIElectronics.System.SystemDevices;
using GHIElectronics.System;
using GHIElectronics.System.IO;
using GHIElectronics.Hardware;

namespace USBiziEICARDetector
{
    public class Program
    {
        static string sEICAR = @"X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*";

        static void Main()
        {
            Boolean bFoundEicar;
            Debug.Print("Starting...");
            while (true)
            {
                // must start system first, no event is associated
                SystemManager.Start(null);
                // wait till we have a device
                while (SystemManager.GetDevices().Length == 0)
                    Thread.Sleep(500);
                // get a list of devices
                Device[] devices = SystemManager.GetDevices();
                // look for a device
                foreach (Device device in devices)
                {
                    // this loop will run once for every device
                    if (device.deviceType == DeviceType.Drive)
                    {
                        try
                        {
                            // USB drive is inserted
                            // Create a new storage device
                            PersistentStorage PS = new PersistentStorage(device.deviceID);
                            // now everything works just like on SD cards....
                            // Mount the file system
                            PS.MountFileSystem();
                            // Assume one storage device is available, access it through NETMF
                            string rootDirectory = VolumeInfo.GetVolumes()[0].RootDirectory;
                            bFoundEicar = false;
                            string[] files = Directory.GetFiles(rootDirectory);
                            Debug.Print("Files on root of USB drive...");
                            foreach (string file in files)
                            {
                                Debug.Print(file);
                                Boolean bFileIsEICAR = false;
                                FileStream fs = File.OpenRead(file);
                                Debug.Print(fs.Length.ToString());
                                if (fs.Length == sEICAR.Length)
                                {
                                    char[] acEICAR = sEICAR.ToCharArray();
                                    for (int iIter = 0; iIter < sEICAR.Length; iIter++)
                                    {
                                        int iByte = fs.ReadByte();
                                        if (acEICAR[iIter] != iByte)
                                            break;
                                        if (iIter == sEICAR.Length - 1)
                                        {
                                            bFoundEicar = true;
                                            bFileIsEICAR = true;
                                        }
                                    }
                                }
                                fs.Close();
                                if (bFileIsEICAR)
                                {
                                    byte[] abHappyNewYear2010 = {
                                        0x0D, 0x0A, 0x0D, 0x0A, 0x0D, 0x0A, 0x20, 0x58, 0x58, 0x58, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20,
                                        0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x0D, 0x0A, 0x20,
                                        0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x20, 0x20,
                                        0x20, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x58, 0x58, 0x58, 0x20, 0x58, 0x58, 0x58,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x58,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20,
                                        0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58,
                                        0x0D, 0x0A, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20,
                                        0x20, 0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20,
                                        0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20,
                                        0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20,
                                        0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x58, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20,
                                        0x20, 0x20, 0x58, 0x0D, 0x0A, 0x20, 0x58, 0x58, 0x58, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x20, 0x58, 0x20, 0x20, 0x58,
                                        0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58,
                                        0x58, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                                        0x20, 0x58, 0x0D, 0x0A, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58,
                                        0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x58, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x58, 0x58, 0x0D, 0x0A, 0x0D, 0x0A};

                                    File.WriteAllBytes(file, abHappyNewYear2010);
                                    Debug.Print("EICAR found!");
                                }
                            }
                            Debug.Print("... end of list!");
                            // if we need to unmount
                            Thread.Sleep(500);
                            PS.UnmountFileSystem();
                            Thread.Sleep(500);
                            PS.Remove();
                            OutputPort LED = new OutputPort(USBizi.Pins.E2x, false);
                            if (bFoundEicar)
                            {
                                Debug.Print("bFoundEicar = true");
                                BlinkXTimes(LED, 4, 300);
                            }
                            else
                            {
                                Debug.Print("bFoundEicar = false");
                                BlinkXTimes(LED, 2, 300);
                            }
                        }
                        catch (Exception e)
                        {
                            Debug.Print("Exception:");
                            Debug.Print(e.Message);
                        }
                    }
                }
                Thread.Sleep(500);
                SystemManager.Reboot(SystemManager.RebootMode.Normal);
            }
        }

        public static void BlinkXTimes(OutputPort LED, int times, int milliseconds)
        {
            for (int i = 0; i < times; i++)
            {
                LED.Write(true);
                Thread.Sleep(milliseconds);
                LED.Write(false);
                Thread.Sleep(milliseconds);
            }
        }
    }
}

Monday 9 November 2009

Quickpost: “Hiding” a PDF Document

Filed under: Entertainment,My Software,PDF,Quickpost — Didier Stevens @ 15:00

Here’s some Python code (it uses my mPDF module) to append a new PDF document to an existing PDF document to “hide” the original document. Recovering the original is trivial, you open the PDF document with a HEX-editor and delete the appended document (starting after the second %%EOF counting from the end of the file). This trick uses incremental updates.

20091107-172245

#!/usr/bin/python

__description__ = 'make-pdf-hide-original, use it to "hide" the original PDF document'
__author__ = 'Didier Stevens'
__version__ = '0.0.1'
__date__ = '2009/11/07'

"""
Source code put in public domain by Didier Stevens, no Copyright
https://DidierStevens.com
Use at your own risk

History:
 2009/11/07: start

Todo:

"""

import mPDF
import time
import zlib
import optparse

def Main():
    oParser = optparse.OptionParser(usage='usage: %prog [options] pdf-file\n' + __description__, version='%prog ' + __version__)
    oParser.add_option('-s', '--line', default='Hello World', help='The line of text to print on the screen (default Hello World')
    (options, args) = oParser.parse_args()

    if len(args) != 1:
        oParser.print_help()
        print ''
        print '  %s' % __description__
        print '  Source code put in the public domain by Didier Stevens, no Copyright'
        print '  Use at your own risk'
        print '  https://DidierStevens.com'

    else:
        pdffile = args[0]
        oPDF = mPDF.cPDF(pdffile)
        oPDF.template1()
        oPDF.stream(5, 0, 'BT /F1 24 Tf 100 700 Td (%s) Tj ET' % options.line)
        oPDF.xrefAndTrailer('1 0 R')

if __name__ == '__main__':
   Main()

Quickpost info

 


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