T1574.012: COR_PROFILER
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 profilers are designed to monitor, troubleshoot, and debug managed code executed by the .NET CLR.[1][2]
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.[2]
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.[3][4][5][6][7]
Security context for executives and security teams
T1574.012: COR_PROFILER describes 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 profilers are designed to monitor, troubleshoot, and debug managed code executed by the .NET CLR.(Citation: Microsoft Profiling Mar 2017)(Citation: Microsoft COR_PROFILER Feb ...
Executive priority
T1574.012: COR_PROFILER 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 T1574.012: COR_PROFILER by reviewing the official ATT&CK relationships, mapped tactics (stealth, execution), supported platforms (Windows), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
- Endpoint process, command-line, and script execution logs
- Network, endpoint, and security-tool telemetry
Detection direction
- Validate whether T1574.012: COR_PROFILER 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.
COR_PROFILER
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 profilers are designed to monitor, troubleshoot, and debug managed code executed by the .NET CLR.[1][2]
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.[2]
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.[3][4][5][6][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 | T1574 | Hijack Execution Flow | This object subtechnique of Hijack Execution Flow. |
Groups, software, and campaigns
G0108: Blue Mockingbird
Blue Mockingbird is a cluster of observed activity involving Monero cryptocurrency-mining payloads in dynamic-link library (DLL) form on Windows systems. The earliest observed Blue Mockingbird tools were created in December 2019.[1]
S1066: DarkTortilla
DarkTortilla is a highly configurable .NET-based crypter that has been possibly active since at least August 2015. DarkTortilla has been used to deliver popular information stealers, RATs, and payloads such as Agent Tesla, AsyncRat, NanoCore, RedLine, Cobalt Strike, and Metasploit.[1]
All related ATT&CK context
Mitigation direction
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 | 2.0 | Current bundle | 6f37870bdfb9… | ||
| 19.1 | 2.0 | Older bundle | 6f37870bdfb9… |
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 Profiling Mar 2017
Microsoft. (2017, March 30). Profiling Overview. Retrieved June 24, 2020.
Open source URL - [2]Microsoft COR_PROFILER Feb 2013
Microsoft. (2013, February 4). Registry-Free Profiler Startup and Attach. Retrieved June 24, 2020.
Open source URL - [3]RedCanary Mockingbird May 2020
Lambert, T. (2020, May 7). Introducing Blue Mockingbird. Retrieved May 26, 2020.
Open source URL - [4]Red Canary COR_PROFILER May 2020
Brown, J. (2020, May 7). Detecting COR_PROFILER manipulation for persistence. Retrieved June 24, 2020.
Open source URL - [5]Almond COR_PROFILER Apr 2019
Almond. (2019, April 30). UAC bypass via elevated .NET applications. Retrieved June 24, 2020.
Open source URL - [6]GitHub OmerYa Invisi-Shell
Yair, O. (2019, August 19). Invisi-Shell. Retrieved June 24, 2020.
Open source URL - [7]subTee .NET Profilers May 2017
Smith, C. (2017, May 18). Subvert CLR Process Listing With .NET Profilers. Retrieved June 24, 2020.
Open source URL - [8]mitre-attackT1574.012Open source URL
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