T1555.001 - Credentials from Password Stores: Keychain

Description from ATT&CK

Adversaries may acquire credentials from Keychain. Keychain (or Keychain Services) is the macOS credential management system that stores account names, passwords, private keys, certificates, sensitive application data, payment data, and secure notes. There are three types of Keychains: Login Keychain, System Keychain, and Local Items (iCloud) Keychain. The default Keychain is the Login Keychain, which stores user passwords and information. The System Keychain stores items accessed by the operating system, such as items shared among users on a host. The Local Items (iCloud) Keychain is used for items synced with Apple’s iCloud service. Keychains can be viewed and edited through the Keychain Access application or using the command-line utility security. Keychain files are located in ~/Library/Keychains/, /Library/Keychains/, and /Network/Library/Keychains/.(Citation: Keychain Services Apple)(Citation: Keychain Decryption Passware)(Citation: OSX Keychain Schaumann) Adversaries may gather user credentials from Keychain storage/memory. For example, the command security dump-keychain –d will dump all Login Keychain credentials from ~/Library/Keychains/login.keychain-db. Adversaries may also directly read Login Keychain credentials from the ~/Library/Keychains/login.keychain file. Both methods require a password, where the default password for the Login Keychain is the current user’s password to login to the macOS host.(Citation: External to DA, the OS X Way)(Citation: Empire Keychain Decrypt)

Atomic Tests

• Atomic Test #1 - Keychain Dump

• Atomic Test #2 - Export Certificate Item(s)

• Atomic Test #3 - Import Certificate Item(s) into Keychain

Atomic Test #1 - Keychain Dump

This command will dump keychain credential information from login.keychain. Source: https://www.loobins.io/binaries/security/

Keychain File path

~/Library/Keychains/ /Library/Keychains/ /Network/Library/Keychains/ Security Reference

Supported Platforms: macOS

auto_generated_guid: 88e1fa00-bf63-4e5b-a3e1-e2ea51c8cca6

Attack Commands: Run with

1

sh

! Elevation Required (e.g. root or admin)

1
sudo security dump-keychain -d login.keychain

Atomic Test #2 - Export Certificate Item(s)

This command finds all certificate items and sends the output to local file in pem format.

Supported Platforms: macOS

auto_generated_guid: 1864fdec-ff86-4452-8c30-f12507582a93

Inputs:

| Name | Description | Type | Default Value | |——|————-|——|—————| | cert_export | Specify the path of the certificates to export. | path | /tmp/certs.pem|

Attack Commands: Run with

1

sh

!

1
security find-certificate -a -p > #{cert_export}

Cleanup Commands:

1
rm #{cert_export}

Atomic Test #3 - Import Certificate Item(s) into Keychain

This command will import a certificate pem file into a keychain.

Supported Platforms: macOS

auto_generated_guid: e544bbcb-c4e0-4bd0-b614-b92131635f59

Inputs:

| Name | Description | Type | Default Value | |——|————-|——|—————| | cert_export | Specify the path of the pem certificate file to import. | path | /tmp/certs.pem|

Attack Commands: Run with

1

sh

!

1
security import #{cert_export} -k