Emotet — Office (OOXML) / .DOC malware analysis

Static analysis result for SHA-256 9d89a5da24c3453a…

MALICIOUS

Office (OOXML) / .DOC

88.0 KB Created: 2021-12-08 18:15:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 90f1019d290583454b2e9d9f0d09e82f SHA-1: 95b6d4ea7b5c8ca3ed804488e00bbd3cbaadfc63 SHA-256: 9d89a5da24c3453a9f2234ee8c5e7571eff56f6ebb77a7f6f8cd0ae3e906e540
202 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1204.002 Malicious File

The sample is a malicious OOXML document containing a VBA macro. The `autoopen` subroutine within the `main` module is triggered upon opening the document. This macro reconstructs a filename using `StrReverse` on the document's keywords property and then uses a `CreateObject` call to execute `c:\windows\explorer ` followed by the reconstructed filename. This indicates the macro's intent is to download and execute a second-stage payload. The ClamAV detection name and heuristic firings strongly suggest the Emotet family.

Heuristics 6

  • ClamAV: Doc.Downloader.EmotetUpdate122100-9914334-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetUpdate122100-9914334-1
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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.microsoft.com/office/drawing/2014/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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
801a3628af7e2c86a56693d8c6f345bce3cff041526262a14049f95c7e0fbce9
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 989 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
vbaProject_00.bin
63c496f24bd5a74662319714c6c21712fb44e574eec5d11dd068fd3c84b120a8
vba-project OOXML VBA project: word/vbaProject.bin 14336 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.