Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 756186368250a990…

MALICIOUS

Office (OLE) / .XLS

55.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-22
MD5: de2ab8ef9a61718af830c6edbf08e2e7 SHA-1: c8ebe184cdddb995ab4b7d980a53cb24460cbe46 SHA-256: 756186368250a9902ae168c2f0c6a77d3fdd70f7a5589c36f8c7bd80cf8756e4
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample is an Excel file containing Excel 4.0 (XLM) macros, specifically an Auto_Open entry that uses dangerous formula APIs. ClamAV identifies this as Emotet, a known downloader. The macro appears to construct a URL for downloading a second-stage payload.

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-aa87d5786a858772-9953435-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-aa87d5786a858772-9953435-0
  • 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
849f3718ec0fd3673746b761d078b5d6767e9cb8cc0df7772d50cc7c5a2548d8		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8080 bytes

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