Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 f0ac1288e675fa54…

MALICIOUS

Office (OLE) / .XLSX

115.6 KB Created: 2022-01-24 14:50:55 Authoring application: Microsoft Excel
MD5: b06a675e2005b8b4fee2ef3224b6c266 SHA-1: c54b2b7f647ae3f285b8cb74692a589568320210 SHA-256: f0ac1288e675fa54329d1cb963412a8c87856e13c90cff474ee6cb962459a340
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1566.001 Phishing: Spearphishing Attachment T1059.001 Command and Scripting Interpreter: PowerShell T1059.003 Command and Scripting Interpreter: Windows Command Shell

The file is an Excel spreadsheet containing Excel 4.0 macros, specifically an Auto_Open macro. This macro is flagged as dangerous due to its use of the RUN function, indicating it's designed to execute arbitrary code. ClamAV identifies this as 'Xls.Downloader.Emotet', strongly suggesting Emotet family activity. The macro's purpose is to download and execute a second-stage payload, a common Emotet delivery technique.

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-bd646319c2d29cd6-9951195-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-bd646319c2d29cd6-9951195-0
  • 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
f65423032a2492710482664c048191ebe835ee4ace2752f1b0fa6e40d416cdf9		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4885 bytes

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