Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 8ac6428e1c404275…

MALICIOUS

Office (OLE) / .XLS

74.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-20
MD5: 44feb8f801c923fca3bcb1ffef33c83a SHA-1: b8ad6d28afeea84e3868cad28a137b80f479cff9 SHA-256: 8ac6428e1c404275ea1393b0bdef054ecab0fedcec7b61ce723e48ad53aedb4e
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

The file is an Excel 4.0 macro-enabled spreadsheet detected as Emotet by ClamAV. The critical heuristics indicate the presence of an Auto_Open macro that uses dangerous functions, specifically the RUN function. The extracted URLs are likely used to download and execute a second-stage payload. The macro itself is too truncated to provide further details on its specific actions.

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
7ab5ef6689937532951c996fe211a2ac046a3dbc546728bfe725212729605929
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6790 bytes