Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 55841d5507cc71e0…

MALICIOUS

Office (OOXML)

26.0 KB Created: 2021-07-09 02:53:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: a323ed423087f305c249106fbd8c1558 SHA-1: 121377ef5a998435d8d0072f0aa1a2de481f0d4a SHA-256: 55841d5507cc71e0a16b01a2f76d9ed4ad9419673caee82d7a7a55504f27f92e
282 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is an OOXML document containing VBA macros, specifically an AutoOpen macro that references PowerShell. This suggests the document is designed to execute a PowerShell command upon opening, likely to download and execute a secondary payload. ClamAV detection further supports its malicious nature as a downloader.

Heuristics 7

  • PowerShell reference in VBA critical OLE_VBA_PS
    PowerShell reference in VBA
  • ClamAV: Doc.Downloader.Pwshell-10001336-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Pwshell-10001336-0
  • 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.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • 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 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
6436d82bd0d13bb33b94262955f09cf21e830bbbe21562bc1a7f00aac2ccb97f
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 9737 bytes
vbaProject_00.bin
2445930e3dcbf38cedc98b6faa9d8d5206d7bfd4117f5f378c46b14822a5251f
vba-project OOXML VBA project: word/vbaProject.bin 34304 bytes
Detection
ClamAV: Doc.Downloader.Pwshell-10001336-0
Obfuscation or payload: unlikely