Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 7bd1caac9273f146…

MALICIOUS

Office (OLE) / .XLS

70.8 KB Created: 2022-01-20 19:00:43 Authoring application: Microsoft Excel
MD5: 02d1b1924125f5441508e9534d6e63f9 SHA-1: ca22efce505105056c809028f719c568ce3d2fea SHA-256: 7bd1caac9273f146c98bf66f7e1c2194e1aa3076a3a1676e8a5cd18739457e08
140 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file is identified as malicious by ClamAV with the signature Doc.Downloader.EmotetExcel01220-9937164-0, indicating it is likely an Emotet downloader. Static analysis revealed the presence of Excel 4.0 macros, specifically an Auto_Open entry, which is a common technique for initial execution. The macro sheet itself contains obfuscated code, typical of Emotet, designed to run automatically when the workbook 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