Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 457a6d3a34153a57…

MALICIOUS

Office (OLE) / .XLS

95.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-07-13
MD5: 6c0c438de8a53753a2c3a46229fc978a SHA-1: 21d8d53eb71e0a4027fc7dcb875746d27573f7a7 SHA-256: 457a6d3a34153a57c63384e2e5cc441866a77bafa91875079ca7a20391a9a608
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a known technique for executing malicious code. Heuristics indicate the use of dangerous formula APIs like RUN, and ClamAV identifies it as an Emotet downloader. The macro's purpose is to automatically execute upon opening, likely to download and run a secondary payload.

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
85773188e79d904ef8ecf815a27f3a8200cc87e1822ab4901cc9bed29c53e636
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8156 bytes