Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 ca1baf60faa94864…

MALICIOUS

Office (OLE) / .XLSX

142.7 KB Created: 2022-01-19 09:31:16 Authoring application: Microsoft Excel
MD5: f01e5d435c0c8ea77c3f1a5421ef0dea SHA-1: 9828a2d6ea9efcde63a6660c3c26af8cb6ab426e SHA-256: ca1baf60faa9486403587e0fac3c548db3aa5b6fb42897e1569020682499e319
140 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a known technique for Emotet to execute malicious code. ClamAV also detected this file as 'Doc.Downloader.EmotetExcel01220-9936774-0', strongly indicating its downloader functionality. The document body content appears to be a lure, presenting itself as a blood pressure tracker, which is a common tactic for social engineering.

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