Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 155c35e56ceaff37…

MALICIOUS

Office (OLE) / .XLS

40.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-15
MD5: adefed201969a350933308b75124897d SHA-1: f4d7803c6b5f36770fe0abd87622e475aa740b00 SHA-256: 155c35e56ceaff3777aa8f70dd7ddbbec8a7f07abb0738b0097f300d4fccfd92
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open entry that utilizes dangerous formula APIs like RUN. This indicates an attempt to automatically execute code upon opening the document. The ClamAV detection and the presence of multiple URLs suggest the macro is designed to download and execute a secondary payload, consistent with Emotet's typical behavior. The reconstructed path C:\Windows\System32\.exe further supports the payload execution.

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-adc2d23d2dc26dd0-9950240-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-adc2d23d2dc26dd0-9950240-0
  • 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
3c680580d6c572fd20a0c9546b3c387c5635a8ba1be4180a74910d19615b1490		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6911 bytes

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