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

Static analysis result for SHA-256 5b729ea665fa8c4e…

MALICIOUS

Office (OOXML) / .DOC

75.6 KB Created: 2021-02-01 11:16:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: a7381f4e85590449ca5c33bec0aa39b3 SHA-1: f299694003dd4e96abd9b9b36857c6f5373b56e4 SHA-256: 5b729ea665fa8c4ee7d64a33f8037ddcd0cd67e018362b8faef0fb385a8cef7f
264 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample contains VBA macros with an AutoOpen function that calls CreateObject and Shell functions, indicating it attempts to download and execute a payload. The script uses XOR obfuscation on strings, and the reconstructed constants '10.23.31.3.0.29.10.29' and '12.85.51.31.29.0.8.29.14.2.11.14.27.14.51.14.22.54.11.21.65.7.27.14' likely represent obfuscated URLs or IP addresses used for payload retrieval. The presence of the 'Doc.Downloader' ClamAV signature further supports this.

Heuristics 8

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • ClamAV: Doc.Downloader.8f0f0f0fe0f0f0f0-OOXML-9981534-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.8f0f0f0fe0f0f0f0-OOXML-9981534-0
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
f171ccd1e9661f6b871a4021b3e3d62cbdae425358e18dcd8527d512938b9150
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2053 bytes
vbaProject_00.bin
3924590aece3606fc201c7f56b790e8de2330bba86124b24c5dd47bcb309dd4d
vba-project OOXML VBA project: word/vbaProject.bin 25600 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).