T1137
Office Application Startup
Windows · Office Suitenothing on this site yetT1137 on attack.mitre.org
Adversaries may leverage Microsoft Office-based applications for persistence between startups. Microsoft Office is a fairly common application suite on Windows-based operating systems within an enterprise network. There are multiple mechanisms that can be used with Office for persistence when an Office-based application is started; this can include the use of Office Template Macros and add-ins.
If this is happening now
Checklists and playbooks to open while the alert is still live.
Playbook for this stage
Suspicious execution on an endpoint
An EDR alert, an unexplained process, or a user reporting something odd.
how MITRE says to see it
Detect Office Startup-Based Persistence via Macros, Forms, and Registry Hooks
- Office-based persistence via Office template macros, Outlook forms/rules/homepage, or registry-persistent scripts. Adversary modifies registry keys or Office application directories to load malicious scripts at startup.
- Startup-based persistence mechanisms within Microsoft Office Suite like template macros and home page redirects being configured through internal automation or client-side settings.
what reduces it
- M1040 Behavior Prevention on Endpoint. On Windows 10, enable Attack Surface Reduction (ASR) rules to prevent Office applications from creating child processes and from writing potentially malicious executable content to disk.
- M1054 Software Configuration. For the Office Test method, create the Registry key used to execute it and set the permissions to "Read Control" to prevent easy access to the key without administrator permissions or requiring Privilege Escalation.
- M1051 Update Software. For the Outlook methods, blocking macros may be ineffective as the Visual Basic engine used for these features is separate from the macro scripting engine. Microsoft has released patches to try to address each issue.
- M1042 Disable or Remove Feature or Program. Follow Office macro security best practices suitable for your environment. Disable Office VBA macros from executing. Disable Office add-ins. If they are required, follow best practices for securing them by requiring them to be signed and disabling user notification for allowing add-ins.