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MWI generated document

yara LOW Yara-Rules
backdoorcommunity
This rule was pulled from an open-source repository and enriched with AI. Validate in a test environment before deploying to production.
View original rule at Yara-Rules →
Retrieved: 2026-05-13T11:00:00Z · Confidence: medium

Hunt Hypothesis

Adversaries may generate documents using Microsoft Word Interop (MWI) to exfiltrate data or create malicious payloads, leveraging the legitimate tool to evade detection. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify potential data exfiltration or persistence tactics that bypass traditional detection methods.

YARA Rule

rule mwi_document: exploitdoc maldoc
{
    meta:
        description = "MWI generated document"
        author = "@Ydklijnsma"
        source = "http://blog.0x3a.com/post/117760824504/analysis-of-a-microsoft-word-intruder-sample"

      strings:
        $field_creation_tag = "{\\field{\\*\\fldinst { INCLUDEPICTURE"
        $mwistat_url = ".php?id="
        $field_closing_tag = "\\\\* MERGEFORMAT \\\\d}}{\\fldrslt}}"

    condition:
        all of them
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

This rule contains 3 string patterns in its detection logic.

False Positive Guidance

Original source: https://github.com/Yara-Rules/rules/blob/main/maldocs/maldoc_somerules.yar