Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 76a39ebb428896a9…

MALICIOUS

Office (OOXML)

108.2 KB Created: 2021-07-26 05:40:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 452130680adfc5cf9e023a1859d30166 SHA-1: e4e9e45ccf4959c7820a3687b56a0558b23a50eb SHA-256: 76a39ebb428896a981ca71ef2059abbdeb6e5e4e2ff4395a8519d396492f1492
242 Risk Score

Malware Insights

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

The sample is an OOXML document containing obfuscated VBA macros, including a Document_Open auto-exec macro. The script uses CreateObject and CallByName to dynamically construct and execute commands, likely to download and run a second-stage payload from the URL associated with the embedded image beacon. The document body impersonates an Amazon order confirmation to trick the user into opening the malicious file.

Heuristics 8

  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Remote image (web beacon / tracking pixel) medium OOXML_IMAGE_BEACON
    Document references an external image URL — loads automatically on open, revealing IP address and timestamp to the server (used for phishing tracking and NTLM hash theft on corporate networks)
  • External relationship medium OOXML_EXTERNAL_REL
    External target in word/_rels/document.xml.rels: https://divine-bar-3d75.visual-candy.workers.dev/colorful.png
  • 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.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/2012/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
    • https://divine-bar-3d75.visual-candy.workers.dev/colorful.png

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
4fa9992588440d3d339e8e98c40bb70715b54a08afec2b5cbd1eb3f7459a1767
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 120717 bytes
vbaProject_00.bin
84524f8baba87c7869446da4b94eae517c8914ec03d702ef79c121bf990741f8
vba-project OOXML VBA project: word/vbaProject.bin 118784 bytes