Malicious Office (OOXML) / .DOCM — malware analysis report

Static analysis result for SHA-256 025a87c5e9e304a9…

MALICIOUS

Office (OOXML) / .DOCM

566.6 KB Created: 2020-12-24 08:21:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 7af2418704988ad587d559b22f3168d7 SHA-1: d59a7c5ca77634d34ce2b3619efadb3f1658c24d SHA-256: 025a87c5e9e304a94a829aaf633c1247435672dfcb0e26fc88a0ef9023aa3632
482 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

This DOCM file contains a heavily obfuscated VBA macro that automatically executes upon opening. The macro utilizes WScript.Shell and CreateObject to download and execute a second-stage payload, as indicated by the 'OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER' and 'OLE_VBA_SHELL' heuristic firings. The ClamAV detection 'Doc.Dropper.Agent-6412232-1' further confirms its malicious nature as a dropper.

Heuristics 11

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://bitbucket.org/seveca-emilia/onemoreslave/downloads/defenderModule.exe
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas
    • http://schemas.microsoft.com/office/drawing/2014/chartex
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartex
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartex
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/drawing/2016/ink
    • http://schemas.microsoft.com/office/drawing/2017/model3d
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.microsoft.com/office/word/2010/wordml
    • http://schemas.microsoft.com/office/word/2012/wordml
    • http://schemas.microsoft.com/office/word/2018/wordml/cex
    • http://schemas.microsoft.com/office/word/2016/wordml/cid
    • http://schemas.microsoft.com/office/word/2018/wordml
    • http://schemas.microsoft.com/office/word/2015/wordml/symex
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroup
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInk
    • http://schemas.microsoft.com/office/word/2006/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShape
    • https://en.wikipedia.org/wiki/Central_limit_theorem
    • https://en.wikipedia.org/wiki/Theodorus_of_Cyrene
    • http://www.w3.org/2000/svg
    • https://en.wikipedia.org/wiki/Theodorus_of_Cyrene�

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
6aa8655497e829a2737b9bc048934f4214cea9f5dfe981b0cf3e5a890985637e
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2266679 bytes
vbaProject_00.bin
502f499e83359a6937d00d110f39977f36fda7a4beef88fa1ed23e7929442f2a
vba-project OOXML VBA project: word/vbaProject.bin 3354112 bytes
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
emf_00.emf
369338825a91500392b48326331c6451b0494d846e45e388aea87d357464b35a
ooxml-emf OOXML EMF part: word/media/image1.emf 1108 bytes