T1480.002: Mutual Exclusion
Adversaries may constrain execution or actions based on the presence of a mutex associated with malware. A mutex is a locking mechanism used to synchronize access to a resource. Only one thread or process can acquire a mutex at a given time.[1]
While local mutexes only exist within a given process, allowing multiple threads to synchronize access to a resource, system mutexes can be used to synchronize the activities of multiple processes.[1] By creating a unique system mutex associated with a particular malware, adversaries can verify whether or not a system has already been compromised.[2]
In Linux environments, malware may instead attempt to acquire a lock on a mutex file. If the malware is able to acquire the lock, it continues to execute; if it fails, it exits to avoid creating a second instance of itself.[3][4]
Mutex names may be hard-coded or dynamically generated using a predictable algorithm.[5]
Security context for executives and security teams
T1480.002: Mutual Exclusion describes Adversaries may constrain execution or actions based on the presence of a mutex associated with malware. A mutex is a locking mechanism used to synchronize access to a resource. Only one thread or process can acquire a mutex at a given time.(Citation: Microsoft Mutexes) While local mutexes only exist within a given process, allowing multiple threads to synchronize access to a resource, system mutexes can be used to synchronize the activities of multiple processes.(Citation: Microsoft Mutexes) By creating a unique s...
Executive priority
T1480.002: Mutual Exclusion 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 T1480.002: Mutual Exclusion by reviewing the official ATT&CK relationships, mapped tactics (stealth), supported platforms (Linux, macOS, Windows), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
- Network, endpoint, and security-tool telemetry
Detection direction
- Validate whether T1480.002: Mutual Exclusion 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.
Mutual Exclusion
Adversaries may constrain execution or actions based on the presence of a mutex associated with malware. A mutex is a locking mechanism used to synchronize access to a resource. Only one thread or process can acquire a mutex at a given time.[1]
While local mutexes only exist within a given process, allowing multiple threads to synchronize access to a resource, system mutexes can be used to synchronize the activities of multiple processes.[1] By creating a unique system mutex associated with a particular malware, adversaries can verify whether or not a system has already been compromised.[2]
In Linux environments, malware may instead attempt to acquire a lock on a mutex file. If the malware is able to acquire the lock, it continues to execute; if it fails, it exits to avoid creating a second instance of itself.[3][4]
Mutex names may be hard-coded or dynamically generated using a predictable algorithm.[5]
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 | T1480 | Execution Guardrails | This object subtechnique of Execution Guardrails. |
Groups, software, and campaigns
G0082: APT38
APT38 is a North Korean state-sponsored threat group that specializes in financial cyber operations; it has been attributed to the Reconnaissance General Bureau.[1] Active since at least 2014, APT38 has targeted banks, financial institutions, casinos, cryptocurrency exchanges, SWIFT system endpoints, and ATMs in at least 38 countries worldwide. Significant operations include the 2016 Bank of Bangladesh heist, during which APT38 stole $81 million, as well as attacks against Bancomext [2] and Banco de Chile [2]; some of their attacks have been destructive.[1][2][3][4]
North Korean group definitions are known to have significant overlap, and some security researchers report all North Korean state-sponsored cyber activity under the name Lazarus Group instead of tracking clusters or subgroups.
G0094: Kimsuky
Kimsuky is a Democratic People's Republic of Korea (DPRK)-based cyber espionage group that has been active since at least 2012. The group initially targeted South Korean government agencies, think tanks, and subject-matter experts in various fields. Its operations expanded to include the United Nations and organizations in the government, education, business services, and manufacturing sectors across the United States, Japan, Russia, and Europe. Kimsuky has focused collection on foreign policy and national security issues tied to the Korean Peninsula, nuclear policy, and sanctions. Kimsuky operations have overlapped with those of other North Korean state-sponsored cyber espionage actors as a result of ad hoc collaborations or other limited resource sharing.[1][2][3][4][5][6]
Kimsuky was assessed to be responsible for the 2014 Korea Hydro & Nuclear Power Co. compromise; other notable campaigns include Operation STOLEN PENCIL (2018), Operation Kabar Cobra (2019), and Operation Smoke Screen (2019).[7][8][9] In 2023, Kimsuky was observed using commercial large language models (LLMs) to assist with vulnerability research, scripting, social engineering and reconnaissance.[10]
DPRK threat actor cluster boundaries overlap in open source reporting, with some security researchers consolidating all attributed North Korean state-sponsored cyber activity under Lazarus Group, rather than tracking operationally distinct subgroups.
S1239: TONESHELL
S1236: CLAIMLOADER
CLAIMLOADER is a malware variant that frequently accompanies legitimate executables that are used for DLL side-loading known to be leveraged by Mustang Panda and was first observed utilized in 2021.[1][2]
S0013: PlugX
S9019: PureCrypter
PureCrypter is a fully-featured malware loader, developed by a threat actor called “PureCoder," that has been in use since at least 2021 to distribute a variety of remote access trojans and information stealers.[1]
S1202: LockBit 3.0
LockBit 3.0 is an evolution of the LockBit Ransomware-as-a-Service (RaaS) offering with similarities to BlackMatter and BlackCat ransomware. LockBit 3.0 has been in use since at least June 2022 and features enhanced defense evasion and exfiltration tactics, robust encryption methods for Windows and VMware ESXi systems, and a more refined RaaS structure over its predecessors such as LockBit 2.0.[1][2][3][4]
S0168: Gazer
S1247: Embargo
Embargo is a ransomware variant written in Rust that has been active since at least May 2024.[1][2] Embargo ransomware operations are associated with “double extortion” ransomware activity, where data is exfiltrated from victim environments prior to encryption, with threats to publish files if a ransom is not paid.[1][2] Embargo ransomware has been known to be delivered through a loader known as MDeployer which also leverages a malware component known as MS4Killer that facilitates termination of processes operating on the victim hosts.[2] Embargo is also reportedly a Ransomware as a Service (RaaS).[2]
S1161: BPFDoor
BPFDoor is a Linux based passive long-term backdoor used by China-based threat actors. First seen in 2021, BPFDoor is named after its usage of Berkley Packet Filter (BPF) to execute single task instructions. BPFDoor supports multiple protocols for communicating with a C2 including TCP, UDP, and ICMP and can start local or reverse shells that bypass firewalls using iptables.[1][2]
S1070: Black Basta
Black Basta is ransomware written in C++ that has been offered within the ransomware-as-a-service (RaaS) model since at least April 2022; there are variants that target Windows and VMWare ESXi servers. Black Basta operations have included the double extortion technique where in addition to demanding ransom for decrypting the files of targeted organizations the cyber actors also threaten to post sensitive information to a leak site if the ransom is not paid. Black Basta affiliates have targeted multiple high-value organizations, with the largest number of victims based in the U.S. Based on similarities in TTPs, leak sites, payment sites, and negotiation tactics, security researchers assess the Black Basta RaaS operators could include current or former members of the Conti group.[1][2][3][4][5][6]
S1183: StrelaStealer
StrelaStealer is an information stealer malware variant first identified in November 2022 and active through late 2024. StrelaStealer focuses on the automated identification, collection, and exfiltration of email credentials from email clients such as Outlook and Thunderbird.[1][2][3][4]
S9023: HiddenFace
HiddenFace is a modular backdoor developed and used exclusively by MirrorFace since at least 2021. HiddenFace can communicate both actively and passively and has been used against political and academic targets.[1][2][3]
S0496: REvil
REvil is a ransomware family that has been linked to the GOLD SOUTHFIELD group and operated as ransomware-as-a-service (RaaS) since at least April 2019. REvil, which as been used against organizations in the manufacturing, transportation, and electric sectors, is highly configurable and shares code similarities with the GandCrab RaaS.[1][2][3]
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 | 9d67ae36ff55… | ||
| 19.1 | 2.0 | Older bundle | 9d67ae36ff55… |
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 Mutexes
Microsoft. (2022, March 11). Mutexes. Retrieved September 19, 2024.
Open source URL - [2]Sans Mutexes 2012
Lenny Zeltser. (2012, July 24). Looking at Mutex Objects for Malware Discovery & Indicators of Compromise. Retrieved September 19, 2024.
Open source URL - [3]Intezer RedXOR 2021
Joakim Kennedy and Avigayil Mechtinger. (2021, March 10). New Linux Backdoor RedXOR Likely Operated by Chinese Nation-State Actor. Retrieved September 19, 2024.
Open source URL - [4]Deep Instinct BPFDoor 2023
Shaul Vilkomir-Preisman and Eliran Nissan. (2023, May 10). BPFDoor Malware Evolves – Stealthy Sniffing Backdoor Ups Its Game. Retrieved September 19, 2024.
Open source URL - [5]ICS Mutexes 2015
Lenny Zeltser. (2015, March 9). How Malware Generates Mutex Names to Evade Detection. Retrieved September 19, 2024.
Open source URL - [6]mitre-attackT1480.002Open source URL
Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.