Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 402b387ff9eaca12…

MALICIOUS

Office (OLE) / .XLSX

141.2 KB Created: 2022-01-19 09:31:16 Authoring application: Microsoft Excel
MD5: bf9341df1bbe722eab536c6a3cfe84a4 SHA-1: 246ff3282a422893e42ce8e3a24a9a6f9e3f7072 SHA-256: 402b387ff9eaca12395e5ea30d7252c77d49ce1d1478784bdb329641136043ea
140 Risk Score

Malware Insights

Emotet · confidence 95%

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, a known technique for Emotet. ClamAV detection further confirms this, identifying it as Doc.Downloader.EmotetExcel01220-9936774-0. The macro sheet contains an Auto_Open defined name, suggesting it's designed to execute automatically upon opening the spreadsheet, likely 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

Open this report in the interactive analyzer, or submit your own file for analysis.