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

Static analysis result for SHA-256 ee9f450ad795bd9c…

MALICIOUS

Office (OOXML) / .DOC

3.33 MB Created: 2022-07-21 22:19:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2022-07-26
MD5: 3e43e586ceb8faeb735fe86e8945cd92 SHA-1: 9e92bc926332cba7e7d00109b6edda386bab2f75 SHA-256: ee9f450ad795bd9caf1ad830a3be0ca0c6f3926aa59d8e9fab80e1d48fac2e27
342 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1105 Ingress Tool Transfer T1027 Obfuscated Files or Information T1204.002 Malicious File

The sample contains a VBA macro with a Document_Open subroutine that executes shellcode loaded from document properties. The macro uses VirtualProtect to allocate executable memory and SetTimer to execute the shellcode, indicating a downloader or initial execution stage. The VBA project part was renamed to evade detection, and the shellcode loader is stored in a document property, suggesting a sophisticated downloader. The ClamAV signature 'Doc.Downloader.8a5a5aca5aca5a7a-OOXML-9981537-0' further confirms its downloader functionality.

Heuristics 9

  • VBA property-stored shellcode loader critical OLE_VBA_PROPERTY_SHELLCODE_LOADER
    VBA auto-exec macro takes the address (VarPtr) of a byte buffer decoded from a document property, marks memory executable (VirtualProtect/VirtualAlloc), and transfers control through a callback API (e.g. SetTimer/EnumWindows). The payload is hidden in the document properties rather than the macro source — the SVCReady loader pattern, a native shellcode runner rather than a parser CVE.
  • ClamAV: Doc.Downloader.8a5a5aca5aca5a7a-OOXML-9981537-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.8a5a5aca5aca5a7a-OOXML-9981537-0
  • OOXML part with non-standard content type and high-entropy data high OOXML_BOGUS_CUSTOM_PART
    The package declares a part with an invented content type (not an OpenXML/Office/standard media type) holding large, high-entropy (likely encrypted/packed) data. Legitimate OOXML files do not carry opaque binary blobs under custom content types; this is the embedded next-stage payload pattern used by loaders such as SVCReady.
  • VBA project part renamed to evade filename detection high OOXML_VBA_PROJECT_RENAMED
    The VBA project is bound through the OOXML relationship/content type but its part is not named vbaProject.bin. Legitimate Office producers always emit vbaProject.bin; renaming it hides the macros from path-only scanners (observed in the SVCReady loader).
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • VBA reads reversed config from document properties high OLE_VBA_REVERSED_DOCPROP_CONFIG
    VBA applies StrReverse to values read from the document's custom/built-in properties. Storing reversed configuration (URLs, CLSIDs, env-var names, payload names) in document properties keeps indicators out of the macro source — an obfuscation technique used by the SVCReady loader.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: word/srOqDdwgPx.bin)
  • 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 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.microsoft.com/office/2019/extlst
    • 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/2020/wordml/sdtdatahash
    • 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
a73d92ae271354be871eabc95affa48d93779893b1c87fd40a5be393bcb2e255
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 6499 bytes
vbaProject_00.bin
4b912cbdf84e7af3df747be7293c6f77082a7f63a7745f3ca516826b322afaad
vba-project OOXML VBA project: word/srOqDdwgPx.bin 14848 bytes