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

Static analysis result for SHA-256 cb1a05a6dc369239…

MALICIOUS

Office (OOXML) / .DOC

3.30 MB Created: 2022-07-20 13:03:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2022-07-20
MD5: 3e6ee2d7a3167d62fc4ce75d806549bc SHA-1: 7b7d891d99d79a47b535cd6b00b6c4c270634657 SHA-256: cb1a05a6dc369239b952ccfef8fe1d460cbedfe18f77851e5f140820ca78285c
262 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1204.002 Malicious File

The file is a malicious OOXML document containing a VBA project with a Document_Open macro. The macro is designed to bypass Office security by luring the user to enable macros. The presence of a renamed VBA project part and a high-entropy custom part suggests obfuscation. ClamAV identified the file as a downloader, indicating it likely fetches and executes a secondary payload.

Heuristics 8

  • ClamAV: Doc.Downloader.SVCReady-c5c43a913b3eccc9-9953477-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.SVCReady-c5c43a913b3eccc9-9953477-0
  • 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
  • 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/zwpjAyRxFB.bin)
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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
31e9cedc033420f840448f007fc33b54028c901373293a0568f6da55dd52703e
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 3040 bytes
vbaProject_00.bin
c7f5f2adb114a6d5b1f6254b3bc941b5bc4cfeaa74d134bd6278d6fb0264319a
vba-project OOXML VBA project: word/zwpjAyRxFB.bin 8192 bytes