Hiren's BootCD in the AD

Usage of Hiren's BootCD PE for Active Directory Environments

Introduction

"Hiren's BootCD PE (Preinstallation Environment) is a restored edition of Hiren's BootCD based on Windows 10 PE x64. Since there are no official updates after November 2012, PE version is being developed by Hiren's BootCD fans. It includes the least , best updated free tools used in Hiren's BootCD"

This document explains usage of Hiren's BootCD PE for pass-the-hash attack in domain environment . Malicious user can obtain mscachv2 hashes of domain users and nt hashes of local users using Hiren's BootCD PE. NT hashes can be used to conduct pass the hash attack, mscachv2 hashes can be cracked with offline brute force attacks.

Attack Path - Hiren's Boot in AD

• Lateral Movement with Hiren's BootCD PE

• Getting ntlm hash of local users and conducting lateral movement.

Requirements

To conduct this attack paths, certain requirements are mandatory.

1. Attacker must be domain user.

2. Python is installed on Windows.(B3KC4T)

3. Hiren's BootCD PE and bootable usb.

Proof Of Concept

Attack- Hiren's Boot in AD

1. For this attack I assume that ftuygun is domain user and uses B3KC4T computer.

   If there are local users that use same password on different workstations, ftuygun

   can conduct pass the hash attack in domain environment using Hiren’s BootCD.

2. ftuygun domain user can copy SAM,SECURITY and SYSTEM files from C:\Windows\system32\config directory to his desktop (C:\Users\ftuygun\Desktop) There is no restriction on copying process because Hiren’s BootCD doesn’t run over C: driver that includes Windows OS system files.

3. Using secretsdump.py ftuygun can extract ntlm hashes of local users and Domain Cached Credentials 2 (DCC2) hashes of domain users.

I suppose ftuygun extracted NT and DCC2 (mscachv2) hashes from the files after mkandemir had session on B3KC4T Workstation. In this case , mkandemir domain user mscachv2 hash is obtained.

4. Malicious domain user can crack mscachv2 hash. Also, he can conduct pass the hash attack to other Windows clients with hashes of local admin users. The point to pay attention is domain user doesn’t have to local admin rights for this attacks.

Mitigation

To avoid these attacks that are explained: (pass the hash attack with nt hash, offline brute force attack for Mscachv2 hash):

• Use Bitlocker for driver that contains Windows operationg systems files.

• Assign password to BIOS.

• Disable usb ports.

# Author: Metin Yunus Kandemir