Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 162f6c1960c11bfb…

MALICIOUS

Office (OLE) / .XLS

95.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-08-08
MD5: f91dc936d0630f0359152cb1d012ce87 SHA-1: 49fe187ec29a9d42d10dd59d64d738f4f61026bb SHA-256: 162f6c1960c11bfb4b3de2be4a747e6c370859404aec89d5b9dc2b6d61c7bb42
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File Execution: Malicious File

The sample is an Excel 4.0 spreadsheet containing an Auto_Open macro, identified by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. ClamAV detection confirms this as Emotet, a known downloader. The macro likely executes a second-stage payload, as indicated by the dangerous formula API usage.

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
63d75723b700f36d4377a66abd3aca986ec95a2d1ebc10754b4e480389a60db6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8138 bytes