Adversaries may hook into Windows application programming interface (API) functions to collect user credentials. Malicious hooking mechanisms may capture API 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. 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)
Source: https://github.com/mitre/cti