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

Static analysis result for SHA-256 bd646d3c7cc5c5d0…

MALICIOUS

Office (OOXML) / .DOC

765.6 KB Created: 2020-05-11 15:09:00 UTC Authoring application: Microsoft Office Word 14.0000
MD5: f126639c2ad579105bd98463111bf8e9 SHA-1: 8d174abdcd41fae9eea11e6530a52de0c7b9c9eb SHA-256: bd646d3c7cc5c5d0b75317546d60577f7085d45a20d472f2f971b07638023e20
202 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1027 Obfuscated Files or Information T1105 Ingress Tool Transfer

The sample contains a VBA macro within the 'macros.bas' file, triggered by the Document_Open subroutine. This macro reconstructs a hex-encoded string from the 'CheckBox1.Caption' property, decodes it, and writes it to a file named '<random_chars>.exe' in the 'c:\xiomi\' directory. The script also attempts to use GetObject to execute this payload, indicating a dropper functionality. The ClamAV detection 'Doc.Dropper.HexEncodedEXEHeader-9789587-1' further supports this assessment.

Heuristics 6

  • ClamAV: Doc.Dropper.HexEncodedEXEHeader-9789587-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.HexEncodedEXEHeader-9789587-1
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • Suspicious extracted artifact high 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.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — 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.openxmlformats.org/markup-compatibility/2006
    • 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/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
8922626f83f05234b73b420e92a8efb55936eeea811c4c857eac4719623c1077		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2258 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 41 Chr/ChrW string-construction calls.
vbaProject_00.bin
eeb3db124deae8332cb7483ec2f46858e2b5ee864d24ce124daa479e5c87dc5e		 vba-project OOXML VBA project: word/vbaProject.bin 15872 bytes

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