Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 f52f03cb94b222c5…

MALICIOUS

Office (OLE) / .XLS

142.1 KB Created: 2022-01-19 09:31:16 Authoring application: Microsoft Excel
MD5: d03cfd5461c8746eb20439acaed6c71d SHA-1: dc5b78cd19245ff529729ff59aeee01742f6e79c SHA-256: f52f03cb94b222c5feffb3c6b07bfebc90c8653f913fe06f27d60a15cd65a9f4
140 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic

The critical heuristic firings indicate the presence of Excel 4.0 macros with an Auto_Open entry, a known technique for Emotet. The ClamAV detection further supports this attribution. Although no specific URLs or executable payloads were extracted, the Auto_Open macro is designed to execute arbitrary code, typically to download and run a secondary payload.

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