Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 c42e2e73b96b8378…

MALICIOUS

Office (OLE) / .XLS

77.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-29
MD5: 4506da1e0f1e0bef72fc6cec082ee60d SHA-1: 4d8b1567460f6ad09629ca85dcfcef071b6706d6 SHA-256: c42e2e73b96b837890f4d58423f25b1181aed81eee5d123ea0d0d1295d21509c
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell T1204.002 Malicious File

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a known technique for executing malicious code. ClamAV detection confirms this is Emotet, a downloader family. The macro likely executes a second-stage payload, leveraging the Auto_Open functionality to bypass initial security checks.

Heuristics 4

  • 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.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • ClamAV: Xls.Downloader.Emotet-ea81817e7f807ab1-9952142-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea81817e7f807ab1-9952142-0
  • 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
2ee8676cd4b66c9de334704c25e7c2446fdb37ae844f0f88d019815960e0be7b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8063 bytes