Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 c7c0c70f46c2fbad…

MALICIOUS

Office (OLE) / .XLS

71.3 KB Created: 2022-01-20 19:00:43 Authoring application: Microsoft Excel
MD5: b8f2c91126059f4488d2ea2051b46d0d SHA-1: 95c611053e467ffd0319ab14faedf66043a779c5 SHA-256: c7c0c70f46c2fbad5de497009b739add5a7c7817d656193142138195728ebe37
140 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.005 Visual Basic

The critical heuristics OLE_XLM_AUTOOPEN and OLE_XLM_AUTOOPEN_DEFINEDNAME indicate the presence of an Excel 4.0 Auto_Open macro, which is a known execution vector for Emotet. The ClamAV detection further supports this attribution. The macro sheet contains an Auto_Open entry, suggesting it will execute malicious code when the spreadsheet is opened.

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.EmotetExcel01220-9937164-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetExcel01220-9937164-0
  • 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
7f1f89a8b36a750dced08313a4e4f056192a6eac7194357c673dbbd2670a1a18
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4219 bytes