Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 09829068923a0ae7…

MALICIOUS

Office (OOXML) / .XLSX

233.3 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-10-05
MD5: 6c2cf252183a10fd423a7112ff51414a SHA-1: d9e7368bbb71d812ec3962e7f646b996678f19e4 SHA-256: 09829068923a0ae7f9d1ce129806436aa62d70f51896f69b642971e55c857ee3
140 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell T1204.002 Malicious File

The critical heuristic 'OOXML_XLM_MACROSHEET' indicates the presence of Excel 4.0 macros, a known technique for delivering Emotet. The extracted XLM macro sheets contain strings that appear to be paths to DLL files, likely part of a second-stage payload. The VBA code itself is minimal, suggesting the primary execution logic resides within the XLM macros.

Heuristics 3

  • Excel 4.0 macro sheet (4 sheet(s)) critical OOXML_XLM_MACROSHEET
    Spreadsheet contains an Excel 4.0 (XLM) macro sheet — XLM was a major Office malware vector during 2020-2022 and evaded many VBA-focused controls before Microsoft tightened XLM defaults. Even legitimate XLM use is rare in modern workbooks. The macro sheet is stored as XLSB/BIFF12 binary content, which many XML-only OOXML scanners miss.
  • ClamAV: Xls.Downloader.Emotet-OOXML_XL-af43432fbcb8603c-9980048-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-OOXML_XL-af43432fbcb8603c-9980048-0
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
aaa8e4140b1a48ed914365038bfd1f4385374eef9f5c42b5b515efeb43137002		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1781 bytes
vbaProject_00.bin
94795e2117aed577d611d9b671a9cb8a564f5db202b0165e05c465507892bba4		 vba-project OOXML VBA project: xl/vbaProject.bin 14848 bytes
xlm_sheet_00.bin
a82c7d7b4159ebbaf41dba1d3cfd9fe88ce1c40c68c68c9f6eb5dc0db309e670		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.bin 937 bytes
xlm_sheet_01.bin
3bac225b129ef31adf3c14e08d2a5169bcbf4a9987cb54f55814ad206b54ce63		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.bin 855 bytes
xlm_sheet_02.bin
94a588e2a56275d81100180a7550e955cb5caa379f21a4e0147c1c019cb89dff		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.bin 1129 bytes
xlm_sheet_03.bin
f6024fa1731474d13cd2fbae17dabe57c7ed16bd9bdaac0a90b7313dab9dcb18		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 957 bytes

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