Detect Input Capture in Elastic Security
Adversaries may use methods of capturing user input to obtain credentials or collect information. During normal system usage, users often provide credentials to various different locations, such as login pages/portals or system dialog boxes. Input capture mechanisms may be transparent to the user (e.g. Credential API Hooking) or rely on deceiving the user into providing input into what they believe to be a genuine service (e.g. Web Portal Capture). Common sub-techniques include keylogging via Windows hooks (SetWindowsHookEx), GUI input capture via credential dialog spoofing, web portal capture via fake login pages, and credential API hooking via DLL injection into authentication processes. Threat actors including APT42, Storm-1811, and APT39 have leveraged these techniques, as have malware families such as InvisibleFerret, Chaes, Kobalos, and NPPSPY.
MITRE ATT&CK
- Tactic
- Collection Credential Access
- Technique
- T1056 Input Capture
- Canonical reference
- https://attack.mitre.org/techniques/T1056/
Elastic Detection Query
sequence by host.name with maxspan=1h
[registry where registry.path : ("*\\SYSTEM\\CurrentControlSet\\Control\\NetworkProvider\\Order*", "*\\SYSTEM\\CurrentControlSet\\Services\\*\\NetworkProvider*") and not process.name : ("services.exe", "svchost.exe", "msiexec.exe", "TrustedInstaller.exe")]
[library where process.name : ("winlogon.exe", "lsass.exe", "LogonUI.exe", "consent.exe", "credui.exe") and not dll.path : ("C:\\Windows\\System32\\*", "C:\\Windows\\SysWOW64\\*", "C:\\Program Files\\*", "C:\\Program Files (x86)\\*")]
---
/* Alternative: individual signal queries */
/* Signal 1: Network Provider DLL registration */
registry where registry.path : ("*\\SYSTEM\\CurrentControlSet\\Control\\NetworkProvider\\Order*", "*\\SYSTEM\\CurrentControlSet\\Services\\*\\NetworkProvider*") and not process.name : ("services.exe", "svchost.exe", "msiexec.exe", "TrustedInstaller.exe")
---
/* Signal 2: Suspicious DLL in credential process */
library where process.name : ("winlogon.exe", "lsass.exe", "LogonUI.exe", "consent.exe", "credui.exe") and not dll.path : ("C:\\Windows\\System32\\*", "C:\\Windows\\SysWOW64\\*", "C:\\Program Files\\*", "C:\\Program Files (x86)\\*")
---
/* Signal 3: Input capture API process creation */
process where process.command_line : ("*SetWindowsHookEx*", "*GetAsyncKeyState*", "*GetKeyState*", "*WH_KEYBOARD_LL*", "*WH_MOUSE_LL*", "*pyWinhook*", "*pynput*", "*Get-Clipboard*") or process.name : ("*keylog*", "*keyscan*", "*hookdll*", "*inputcap*")
---
/* Signal 4: Remote thread into credential process */
process where event.action == "CreateRemoteThread" and process.name : ("winlogon.exe", "LogonUI.exe", "credui.exe", "consent.exe")Multi-signal EQL detection for T1056 Input Capture covering Network Provider DLL registration (NPPSPY), suspicious DLL loads into credential processes, input hook API usage in process command lines, and remote thread injection into credential UI processes. Uses both sequence correlation and individual signal rules.
Data Sources
Required Tables
False Positives & Tuning
- Security software (EDR agents, AV engines) legitimately hooks keyboard/mouse APIs for behavior monitoring
- Third-party credential managers or password vaults may load DLLs into winlogon or credui processes
- Network authentication middleware (Cisco NAM, Juniper UAC) registers legitimate Network Provider DLLs during installation
- Accessibility software such as screen readers (JAWS, NVDA) use SetWindowsHookEx for legitimate input monitoring
- Enterprise MFA solutions like Duo or RSA SecurID hook credential processes for authentication flow
Other platforms for T1056
Testing Methodology
Validate this detection against 5 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1NPPSPY Network Provider Registration (Credential Interception Setup)
Expected signal: Sysmon Event ID 12 (RegistryKeyCreate): TargetObject containing HKLM\SYSTEM\CurrentControlSet\Services\TestNPP. Sysmon Event ID 13 (RegistryValueSet): TargetObject containing NetworkProvider\Order with Details showing 'TestNPP' appended to ProviderOrder. Security Event ID 4657 (Registry value modification) if object access auditing is enabled. MDE DeviceRegistryEvents with ActionType=RegistryKeyCreated and RegistryKeyCreated for both the service key and NetworkProvider\Order.
- Test 2Low-Level Keyboard Hook via PowerShell PInvoke (SetWindowsHookEx WH_KEYBOARD_LL)
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe, CommandLine containing 'SetWindowsHookEx', 'WH_KEYBOARD_LL' or value '13', and 'Add-Type'. PowerShell ScriptBlock Log Event ID 4104 with the full PInvoke code including SetWindowsHookEx. MDE DeviceProcessEvents with ProcessCommandLine matching SetWindowsHookEx pattern.
- Test 3Clipboard Monitoring Loop with File Exfiltration Simulation
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe, CommandLine containing 'Get-Clipboard', 'while', 'Start-Sleep', 'Add-Content', '-WindowStyle Hidden'. Sysmon Event ID 11 (File Create): cb_harvest.txt created in %TEMP%. MDE DeviceProcessEvents with ProcessCommandLine matching clipboard + loop pattern. MDE DeviceFileEvents showing file writes to TEMP directory.
- Test 4SSH Client Trojanization Simulation (Kobalos Pattern — Linux)
Expected signal: Auditd: file modification events on /usr/bin/ssh binary (syscall=rename or write). Syslog: file integrity monitoring alerts if AIDE/Tripwire/OSSEC is configured. If Linux auditd with file watches configured: SYSCALL records for rename/unlink on /usr/bin/ssh. Process execution telemetry showing /usr/bin/ssh spawning /tmp/ssh_real as child process. File creation event for /tmp/.ssh_capture.log.
- Test 5Python Keylogger via pynput (Cross-Platform)
Expected signal: Sysmon Event ID 1: Process Create for pip.exe (pynput installation) and python.exe (keylogger execution). CommandLine of python.exe containing 'pynput', 'keyboard', 'Listener', 'on_press'. Sysmon Event ID 7: Image loads for pynput DLL dependencies into python.exe. Network connection (Sysmon Event ID 3) from pip.exe to PyPI for package download during installation phase. MDE DeviceProcessEvents capturing both pip and python command lines.
References (14)
- https://attack.mitre.org/techniques/T1056/
- https://attack.mitre.org/techniques/T1056/001/
- https://attack.mitre.org/techniques/T1056/002/
- https://attack.mitre.org/techniques/T1056/003/
- https://attack.mitre.org/techniques/T1056/004/
- https://www.huntress.com/blog/credential-interception-via-nppspy
- https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setwindowshookexw
- https://www.welivesecurity.com/2021/01/26/kobalos-complex-linux-threat-high-performance-computing-infrastructure/
- https://unit42.paloaltonetworks.com/contagious-interview-beavertail-invisibleferret/
- https://www.sentinelone.com/labs/metador-technical-appendix/
- https://www.cybereason.com/blog/research/chaes-hunting-the-prey
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1056.001/T1056.001.md
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_set/registry_set_credentials_stealing_via_network_provider.yml
- http://opensecuritytraining.info/Keylogging_files/The%20Adventures%20of%20a%20Keystroke.pdf
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