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MITRE ATT&CK® Technique

T1137.006: Add-ins

Adversaries may abuse Microsoft Office add-ins to obtain persistence on a compromised system. Office add-ins can be used to add functionality to Office programs. [1] There are different types of add-ins that can be used by the various Office products; including Word/Excel add-in Libraries (WLL/XLL), VBA add-ins, Office Component Object Model (COM) add-ins, automation add-ins, VBA Editor (VBE), Visual Studio Tools for Office (VSTO) add-ins, and Outlook add-ins. [2][3]

Add-ins can be used to obtain persistence because they can be set to execute code when an Office application starts.

EnterpriseT1137.006Sub-techniqueObject v1.2 Modified
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Glexia's Take

Analyst context for executives and security teams

Analyst confidence Medium

Office add-ins matter because they turn normal Microsoft Office startup behavior into a persistence opportunity. If an adversary can place or enable a malicious add-in, code may run when Word, Excel, Outlook, or related Office components start, helping access survive normal user activity and complicating cleanup.

Executive priority

Treat this as an endpoint and productivity-suite persistence risk, especially for Windows environments that depend heavily on Office. Leaders should ask whether the organization can prove which Office add-ins are authorized, detect suspicious Office startup behavior, and remove unauthorized add-ins during incident response. This also supports audit evidence around control of user-installed or externally introduced Office functionality.

Technical view

ATT&CK identifies this as a persistence sub-technique under Office Application Startup for Windows and Office Suite. SOC and IR teams should validate visibility around Office application startup, add-in loading, add-in inventory/configuration changes, and suspicious Office process/file/API behavior. Because MITRE provides no official detection text for this object, teams should use the related detection strategy, DET0050 Detect Persistence via Malicious Office Add-ins, as a validation target rather than assuming coverage.

Likely telemetry

  • Office add-in inventory and configuration state across Word, Excel, Outlook, VBE, VSTO, COM, VBA, WLL/XLL, and automation add-in types where applicable
  • Office application startup and add-in load evidence
  • Endpoint process telemetry for Office applications and their child or related process behavior
  • Endpoint file activity associated with Office add-in locations or components
  • Endpoint behavioral telemetry covering process, file, and API activity as described by Behavior Prevention on Endpoint

Detection direction

  • Confirm whether monitoring distinguishes approved Office add-ins from newly introduced, unusual, or user-specific add-ins.
  • Tune detections around Office applications loading add-ins and then exhibiting suspicious process, file, or API behavior, while accounting for legitimate business add-ins.
  • Use DET0050 as the ATT&CK-linked detection strategy to test whether malicious Office add-in persistence would be surfaced in the SOC workflow.
  • During investigations, correlate add-in presence with Office startup timing and endpoint behavior rather than relying only on static indicators.
  • Document blind spots where Office add-in inventory, startup events, or endpoint behavioral telemetry are not collected.

Mitigation priorities

  • Establish and maintain an approved Office add-in baseline for Windows and Office Suite systems.
  • Remove unauthorized or unnecessary add-ins using supported Office add-in management/removal processes.
  • Prioritize endpoint behavior-prevention controls that can block suspicious Office-related process, file, and API activity, consistent with M1040.
  • Include Office add-in review in persistence checks during incident response and post-remediation validation.
  • Use add-in control evidence to support compliance and resilience reviews where Office is business-critical.
Analyst notes and limits

The relationship context shows this technique is associated with Naikon and with the Bisonal, LunarMail, and LunarLoader software entries in ATT&CK. That context is useful for threat-informed detection engineering, but it should not be read as evidence that those actors or tools are present in any specific environment.

The supplied ATT&CK object does not include official detection logic, event IDs, file paths, registry locations, or prevention procedures. Local Office versions, add-in types, endpoint tooling, and business-approved add-ins must determine the final detection and response design.

Official MITRE ATT&CK definition

Add-ins

Adversaries may abuse Microsoft Office add-ins to obtain persistence on a compromised system. Office add-ins can be used to add functionality to Office programs. [1] There are different types of add-ins that can be used by the various Office products; including Word/Excel add-in Libraries (WLL/XLL), VBA add-ins, Office Component Object Model (COM) add-ins, automation add-ins, VBA Editor (VBE), Visual Studio Tools for Office (VSTO) add-ins, and Outlook add-ins. [2][3]

Add-ins can be used to obtain persistence because they can be set to execute code when an Office application starts.

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

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.

ATT&CK relationship table

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.

1 rows
Domain ID Name Relationship / procedure
Enterprise T1137 Office Application Startup This object subtechnique of Office Application Startup.
Associated objects

Groups, software, and campaigns

Group Enterprise

G0019: Naikon

Naikon is assessed to be a state-sponsored cyber espionage group attributed to the Chinese People’s Liberation Army’s (PLA) Chengdu Military Region Second Technical Reconnaissance Bureau (Military Unit Cover Designator 78020).[1] Active since at least 2010, Naikon has primarily conducted operations against government, military, and civil organizations in Southeast Asia, as well as against international bodies such as the United Nations Development Programme (UNDP) and the Association of Southeast Asian Nations (ASEAN).[1][2]

While Naikon shares some characteristics with APT30, the two groups do not appear to be exact matches.[3]

Malware Enterprise

S0268: Bisonal

Bisonal is a remote access tool (RAT) that has been used by Tonto Team against public and private sector organizations in Russia, South Korea, and Japan since at least December 2010.[1][2]

Windows
Relationship explorer

All related ATT&CK context

mitigates · Mitigation M1040: Behavior Prevention on Endpoint Enterprise uses · Malware S0268: Bisonal Enterprise uses · Group G0019: Naikon Enterprise detects · Detection Strategy DET0050: Detect Persistence via Malicious Office Add-ins Enterprise subtechnique of · Technique T1137: Office Application Startup Enterprise uses · Malware S1143: LunarLoader Enterprise uses · Malware S1142: LunarMail Enterprise
Mitigations

Mitigation direction

Mitigation Enterprise

M1040: Behavior Prevention on Endpoint

Behavior Prevention on Endpoint refers to the use of technologies and strategies to detect and block potentially malicious activities by analyzing the behavior of processes, files, API calls, and other endpoint events. Rather than relying solely on known signatures, this approach leverages heuristics, machine learning, and real-time monitoring to identify anomalous patterns indicative of an attack. This mitigation can be implemented through the following measures:

Suspicious Process Behavior:

- Implementation: Use Endpoint Detection and Response (EDR) tools to monitor and block processes exhibiting unusual behavior, such as privilege escalation attempts. - Use Case: An attacker uses a known vulnerability to spawn a privileged process from a user-level application. The endpoint tool detects the abnormal parent-child process relationship and blocks the action.

Unauthorized File Access:

- Implementation: Leverage Data Loss Prevention (DLP) or endpoint tools to block processes attempting to access sensitive files without proper authorization. - Use Case: A process tries to read or modify a sensitive file located in a restricted directory, such as /etc/shadow on Linux or the SAM registry hive on Windows. The endpoint tool identifies this anomalous behavior and prevents it.

Abnormal API Calls:

- Implementation: Implement runtime analysis tools to monitor API calls and block those associated with malicious activities. - Use Case: A process dynamically injects itself into another process to hijack its execution. The endpoint detects the abnormal use of APIs like `OpenProcess` and `WriteProcessMemory` and terminates the offending process.

Exploit Prevention:

- Implementation: Use behavioral exploit prevention tools to detect and block exploits attempting to gain unauthorized access. - Use Case: A buffer overflow exploit is launched against a vulnerable application. The endpoint detects the anomalous memory write operation and halts the process.

Change history

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 .

ATT&CK release
19.1
Object version
1.2
Created
Modified
Raw hash
c8221941b9f4d2ba...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 1.2 Current bundle c8221941b9f4…
Raw source

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.

Open mirrored raw JSON Open MITRE-hosted copy
Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

  1. [1]
    Microsoft Office Add-ins

    Microsoft. (n.d.). Add or remove add-ins. Retrieved July 3, 2017.

    Open source URL
  2. [2]
    MRWLabs Office Persistence Add-ins

    Knowles, W. (2017, April 21). Add-In Opportunities for Office Persistence. Retrieved November 17, 2024.

    Open source URL
  3. [3]
    FireEye Mail CDS 2018

    Caban, D. and Hirani, M. (2018, October 3). You’ve Got Mail! Enterprise Email Compromise. Retrieved November 17, 2024.

    Open source URL
  4. [4]
    GlobalDotName Jun 2019

    Shukrun, S. (2019, June 2). Office Templates and GlobalDotName - A Stealthy Office Persistence Technique. Retrieved August 26, 2019.

    Open source URL
  5. [5]
    mitre-attack T1137.006
    Open source URL
Source and licensing

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