Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 fb155f74486710bb…

MALICIOUS

Office (OLE) / .XLS

69.8 KB Created: 2022-01-20 19:00:43 Authoring application: Microsoft Excel
MD5: 7ece1126fb695fcbff58a77f4ad3afb6 SHA-1: 51b418c73afdff7bb8945b8671bfa18027b45964 SHA-256: fb155f74486710bb8e3ca2f50be434fadbb56292e3d42cb0fbdfb217aabb0b0f
140 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.005 Visual Basic T1059.001 PowerShell

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, a common delivery mechanism for Emotet. ClamAV detection further supports this attribution. The macro sheet is configured to automatically execute upon opening, likely to download and execute a second-stage payload.

Heuristics 3

  • 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.
  • ClamAV: Doc.Downloader.EmotetExcel01220-9937164-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetExcel01220-9937164-0
  • 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
7f1f89a8b36a750dced08313a4e4f056192a6eac7194357c673dbbd2670a1a18
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4219 bytes