T1112.md

T1112 - Modify Registry

Description from ATT&CK

Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in persistence and execution.

Access to specific areas of the Registry depends on account permissions, some requiring administrator-level access. The built-in Windows command-line utility Reg may be used for local or remote Registry modification. (Citation: Microsoft Reg) Other tools may also be used, such as a remote access tool, which may contain functionality to interact with the Registry through the Windows API.

Registry modifications may also include actions to hide keys, such as prepending key names with a null character, which will cause an error and/or be ignored when read via Reg or other utilities using the Win32 API. (Citation: Microsoft Reghide NOV 2006) Adversaries may abuse these pseudo-hidden keys to conceal payloads/commands used to maintain persistence. (Citation: TrendMicro POWELIKS AUG 2014) (Citation: SpectorOps Hiding Reg Jul 2017)

The Registry of a remote system may be modified to aid in execution of files as part of lateral movement. It requires the remote Registry service to be running on the target system. (Citation: Microsoft Remote) Often Valid Accounts are required, along with access to the remote system's SMB/Windows Admin Shares for RPC communication.

Atomic Tests

• Atomic Test #1 - Modify Registry of Current User Profile - cmd

• Atomic Test #2 - Modify Registry of Local Machine - cmd

• Atomic Test #3 - Modify registry to store logon credentials

• Atomic Test #4 - Add domain to Trusted sites Zone

• Atomic Test #5 - Javascript in registry

• Atomic Test #6 - Change Powershell Execution Policy to Bypass

Atomic Test #1 - Modify Registry of Current User Profile - cmd

Modify the registry of the currently logged in user using reg.exe via cmd console. Upon execution, the message "The operation completed successfully." will be displayed. Additionally, open Registry Editor to view the new entry in HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced.

Supported Platforms: Windows

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

reg add HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /t REG_DWORD /v HideFileExt /d 1 /f

Cleanup Commands:

reg delete HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced /v HideFileExt /f >nul 2>&1

Atomic Test #2 - Modify Registry of Local Machine - cmd

Modify the Local Machine registry RUN key to change Windows Defender executable that should be ran on startup. This should only be possible when CMD is ran as Administrative rights. Upon execution, the message "The operation completed successfully." will be displayed. Additionally, open Registry Editor to view the modified entry in HKCU\Software\Microsoft\Windows\CurrentVersion\Run.

Supported Platforms: Windows

Inputs:

Name	Description	Type	Default Value
new_executable	New executable to run on startup instead of Windows Defender	string	calc.exe

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

reg add HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run /t REG_EXPAND_SZ /v SecurityHealth /d #{new_executable} /f

Cleanup Commands:

reg delete HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run /v SecurityHealth /f >nul 2>&1

Atomic Test #3 - Modify registry to store logon credentials

Sets registry key that will tell windows to store plaintext passwords (making the system vulnerable to clear text / cleartext password dumping). Upon execution, the message "The operation completed successfully." will be displayed. Additionally, open Registry Editor to view the modified entry in HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest.

Supported Platforms: Windows

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

reg add HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest /v UseLogonCredential /t REG_DWORD /d 1 /f

Cleanup Commands:

reg add HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest /v UseLogonCredential /t REG_DWORD /d 0 /f >nul 2>&1

Atomic Test #4 - Add domain to Trusted sites Zone

Attackers may add a domain to the trusted site zone to bypass defenses. Doing this enables attacks such as c2 over office365. Upon execution, details of the new registry entries will be displayed. Additionally, open Registry Editor to view the modified entry in HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap.

https://www.blackhat.com/docs/us-17/wednesday/us-17-Dods-Infecting-The-Enterprise-Abusing-Office365-Powershell-For-Covert-C2.pdf

Supported Platforms: Windows

Inputs:

Name	Description	Type	Default Value
bad_domain	Domain to add to trusted site zone	String	bad-domain.com

Attack Commands: Run with powershell!

$key= "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\#{bad_domain}\"
$name ="bad-subdomain"
new-item $key -Name $name -Force
new-itemproperty $key$name -Name https -Value 2 -Type DWORD;
new-itemproperty $key$name -Name http  -Value 2 -Type DWORD;
new-itemproperty $key$name -Name *     -Value 2 -Type DWORD;

Cleanup Commands:

$key = "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\#{bad_domain}\"
Remove-item  $key -Recurse -ErrorAction Ignore

Atomic Test #5 - Javascript in registry

Upon execution, a javascript block will be placed in the registry for persistence. Additionally, open Registry Editor to view the modified entry in HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings.

Supported Platforms: Windows

Attack Commands: Run with powershell!

New-ItemProperty "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings" -Name T1112 -Value "<script>"

Cleanup Commands:

Remove-ItemProperty "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings" -Name T1112 -ErrorAction Ignore

Atomic Test #6 - Change Powershell Execution Policy to Bypass

Attackers need to change the powershell execution policy in order to run their malicious powershell scripts. They can either specify it during the execution of the powershell script or change the registry value for it.

Supported Platforms: Windows

Inputs:

Name	Description	Type	Default Value
default_execution_policy	Specify the default poweshell execution policy	String	Default

Attack Commands: Run with powershell!

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope LocalMachine

Cleanup Commands:

Set-ExecutionPolicy -ExecutionPolicy #{default_execution_policy} -Scope LocalMachine