T1056.004: Credential API Hooking
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.[1] 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.[2][3] * **Import address table (IAT) hooking**, which use modifications to a process’s IAT, where pointers to imported API functions are stored.[3][4][5] * **Inline hooking**, which overwrites the first bytes in an API function to redirect code flow.[3][6][5]
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.[7]
Security context for executives and security teams
T1056.004: Credential API Hooking describes 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](https://attack.mitre.org/techniques/T1056/001), this technique focuses specifically on API functions that include parameters that reveal user credentials. In Windows, h...
Executive priority
T1056.004: Credential API Hooking is an official MITRE ATT&CK technique. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.
Technical view
Security teams should validate T1056.004: Credential API Hooking by reviewing the official ATT&CK relationships, mapped tactics (collection, credential-access), supported platforms (Windows, Linux, macOS), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
- Identity, privilege, and authentication events
- Network, endpoint, and security-tool telemetry
Detection direction
- Validate whether T1056.004: Credential API Hooking appears in your detection coverage and tabletop scenarios.
- Use the object to align executive risk language with SOC, incident response, and detection engineering work.
- Do not treat ATT&CK relationship context as attribution without corroborating evidence.
Mitigation priorities
- Map the object to existing controls and identify missing telemetry or response ownership.
- Prioritize mitigations that reduce exposure on the listed platforms and tactics.
- Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits
Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.
This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Credential API Hooking
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.[1] 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.[2][3] * **Import address table (IAT) hooking**, which use modifications to a process’s IAT, where pointers to imported API functions are stored.[3][4][5] * **Inline hooking**, which overwrites the first bytes in an API function to redirect code flow.[3][6][5]
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.[7]
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
Related techniques
This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.
| Domain | ID | Name | Relationship / procedure |
|---|---|---|---|
| Enterprise | T1179 | Hooking | Hooking revoked by this object. |
| Enterprise | T1056 | Input Capture | This object subtechnique of Input Capture. |
Groups, software, and campaigns
G0068: PLATINUM
S0266: TrickBot
TrickBot is a Trojan spyware program written in C++ that first emerged in September 2016 as a possible successor to Dyre. TrickBot was developed and initially used by Wizard Spider for targeting banking sites in North America, Australia, and throughout Europe; it has since been used against all sectors worldwide as part of "big game hunting" ransomware campaigns.[1][2][3][4]
S0416: RDFSNIFFER
RDFSNIFFER is a module loaded by BOOSTWRITE which allows an attacker to monitor and tamper with legitimate connections made via an application designed to provide visibility and system management capabilities to remote IT techs.[1]
S0353: NOKKI
S1154: VersaMem
VersaMem is a web shell designed for deployment to Versa Director servers following exploitation. Discovered in August 2024, VersaMem was used during Versa Director Zero Day Exploitation by Volt Typhoon to target ISPs and MSPs. VersaMem is deployed as a Java Archive (JAR) and allows for credential capture for Versa Director logon activity as well as follow-on execution of arbitrary Java payloads.[1]
S0386: Ursnif
Ursnif is a banking trojan and variant of the Gozi malware observed being spread through various automated exploit kits, Spearphishing Attachments, and malicious links.[1][2] Ursnif is associated primarily with data theft, but variants also include components (backdoors, spyware, file injectors, etc.) capable of a wide variety of behaviors.[3]
S0330: Zeus Panda
Zeus Panda is a Trojan designed to steal banking information and other sensitive credentials for exfiltration. Zeus Panda’s original source code was leaked in 2011, allowing threat actors to use its source code as a basis for new malware variants. It is mainly used to target Windows operating systems ranging from Windows XP through Windows 10.[1][2]
S0251: Zebrocy
S0182: FinFisher
FinFisher is a government-grade commercial surveillance spyware reportedly sold exclusively to government agencies for use in targeted and lawful criminal investigations. It is heavily obfuscated and uses multiple anti-analysis techniques. It has other variants including Wingbird. [1] [2] [3] [4] [5]
S0484: Carberp
S0412: ZxShell
S0363: Empire
Empire is an open-source, cross-platform remote administration and post-exploitation framework that is publicly available on GitHub. While the tool itself is primarily written in Python, the post-exploitation agents are written in pure PowerShell for Windows and Python for Linux/macOS. Empire was one of five tools singled out by a joint report on public hacking tools being widely used by adversaries.[1][2][3]
All related ATT&CK context
Object version and sync metadata
The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.
Imported snapshots across ATT&CK releases(2)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.2 | 1.2 | Current bundle | 87e5f10af333… | ||
| 19.1 | 1.2 | Older bundle | 87e5f10af333… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]Microsoft TrojanSpy:Win32/Ursnif.gen!I Sept 2017
Microsoft. (2017, September 15). TrojanSpy:Win32/Ursnif.gen!I. Retrieved December 18, 2017.
Open source URL - [2]Microsoft Hook Overview
Microsoft. (n.d.). Hooks Overview. Retrieved December 12, 2017.
Open source URL - [3]Elastic Process Injection July 2017
Hosseini, A. (2017, July 18). Ten Process Injection Techniques: A Technical Survey Of Common And Trending Process Injection Techniques. Retrieved December 7, 2017.
Open source URL - [4]Adlice Software IAT Hooks Oct 2014
Tigzy. (2014, October 15). Userland Rootkits: Part 1, IAT hooks. Retrieved December 12, 2017.
Open source URL - [5]MWRInfoSecurity Dynamic Hooking 2015
Hillman, M. (2015, August 8). Dynamic Hooking Techniques: User Mode. Retrieved December 20, 2017.
Open source URL - [6]HighTech Bridge Inline Hooking Sept 2011
Mariani, B. (2011, September 6). Inline Hooking in Windows. Retrieved November 17, 2024.
Open source URL - [7]Intezer Symbiote 2022
Joakim Kennedy and The BlackBerry Threat Research & Intelligence Team. (2022, June 9). Symbiote Deep-Dive: Analysis of a New, Nearly-Impossible-to-Detect Linux Threat. Retrieved March 24, 2025.
Open source URL - [8]EyeofRa Detecting Hooking June 2017
Eye of Ra. (2017, June 27). Windows Keylogger Part 2: Defense against user-land. Retrieved December 12, 2017.
Open source URL - [9]GMER Rootkits
GMER. (n.d.). GMER. Retrieved December 12, 2017.
- [10]Jay GetHooks Sept 2011
Satiro, J. (2011, September 14). GetHooks. Retrieved December 12, 2017.
Open source URL - [11]Microsoft Process Snapshot
Microsoft. (n.d.). Taking a Snapshot and Viewing Processes. Retrieved December 12, 2017.
Open source URL - [12]PreKageo Winhook Jul 2011
Prekas, G. (2011, July 11). Winhook. Retrieved December 12, 2017.
Open source URL - [13]StackExchange Hooks Jul 2012
Stack Exchange - Security. (2012, July 31). What are the methods to find hooked functions and APIs?. Retrieved December 12, 2017.
Open source URL - [14]Volatility Detecting Hooks Sept 2012
Volatility Labs. (2012, September 24). MoVP 3.1 Detecting Malware Hooks in the Windows GUI Subsystem. Retrieved December 12, 2017.
Open source URL - [15]Zairon Hooking Dec 2006
Felici, M. (2006, December 6). Any application-defined hook procedure on my machine?. Retrieved December 12, 2017.
Open source URL - [16]mitre-attackT1056.004Open source URL
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