Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 76faa078d1f1713f…

MALICIOUS

Office (OLE) / .XLSX

142.2 KB Created: 2022-01-19 09:31:16 Authoring application: Microsoft Excel
MD5: 3452fd7ff7848e32e1746d8a03bc98dd SHA-1: 0f40b73b9d1fa7991567efbbcf95c463659e04c9 SHA-256: 76faa078d1f1713f316cf3d152958b0db77d8e9255dd084d902b460fb3ea97cb
140 Risk Score

Malware Insights

Emotet · confidence 95%

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, a common technique for Emotet. ClamAV also specifically detected this as an Emotet Excel downloader variant. The document body, while appearing benign as a blood pressure tracker, is likely a lure to disguise the malicious macro execution. No specific URLs or further script details were extracted, but the presence of the Auto_Open macro strongly suggests the execution of a downloader.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • ClamAV: Doc.Downloader.EmotetExcel01220-9936774-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetExcel01220-9936774-0
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
592af8991900f2f7058dc7ea90a33320ae293c7e541db4222a7b7f9c04f59d96
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8469 bytes