T1574.012 COR_PROFILER Mappings

Adversaries may leverage the COR_PROFILER environment variable to hijack the execution flow of programs that load the .NET CLR. The COR_PROFILER is a .NET Framework feature which allows developers to specify an unmanaged (or external of .NET) profiling DLL to be loaded into each .NET process that loads the Common Language Runtime (CLR). These profiliers are designed to monitor, troubleshoot, and debug managed code executed by the .NET CLR.(Citation: Microsoft Profiling Mar 2017)(Citation: Microsoft COR_PROFILER Feb 2013)

The COR_PROFILER environment variable can be set at various scopes (system, user, or process) resulting in different levels of influence. System and user-wide environment variable scopes are specified in the Registry, where a Component Object Model (COM) object can be registered as a profiler DLL. A process scope COR_PROFILER can also be created in-memory without modifying the Registry. Starting with .NET Framework 4, the profiling DLL does not need to be registered as long as the location of the DLL is specified in the COR_PROFILER_PATH environment variable.(Citation: Microsoft COR_PROFILER Feb 2013)

Adversaries may abuse COR_PROFILER to establish persistence that executes a malicious DLL in the context of all .NET processes every time the CLR is invoked. The COR_PROFILER can also be used to elevate privileges (ex: Bypass User Account Control) if the victim .NET process executes at a higher permission level, as well as to hook and Impair Defenses provided by .NET processes.(Citation: RedCanary Mockingbird May 2020)(Citation: Red Canary COR_PROFILER May 2020)(Citation: Almond COR_PROFILER Apr 2019)(Citation: GitHub OmerYa Invisi-Shell)(Citation: subTee .NET Profilers May 2017)



Capability ID Capability Description Mapping Type ATT&CK ID ATT&CK Name
AC-2 Account Management Protects T1574.012 COR_PROFILER
AC-3 Access Enforcement Protects T1574.012 COR_PROFILER
AC-5 Separation of Duties Protects T1574.012 COR_PROFILER
AC-6 Least Privilege Protects T1574.012 COR_PROFILER
CM-5 Access Restrictions for Change Protects T1574.012 COR_PROFILER
CM-7 Least Functionality Protects T1574.012 COR_PROFILER
IA-2 Identification and Authentication (organizational Users) Protects T1574.012 COR_PROFILER
SI-10 Information Input Validation Protects T1574.012 COR_PROFILER
SI-7 Software, Firmware, and Information Integrity Protects T1574.012 COR_PROFILER
action.malware.variety.Disable controls Disable or interfere with security controls related-to T1574.012 Hijack Execution Flow: COR_PROFILER