Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 cd82fbcfd6ee56df…

MALICIOUS

Office (OLE) / .XLS

95.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-07-13
MD5: 08315ac5fca059b02a8855543bae4226 SHA-1: a785e74271bb9d2d457be589774864768a02b972 SHA-256: cd82fbcfd6ee56df1f957d2b591f55ff5636266af4d25196623b366e3badab7f
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059 Command and Scripting Interpreter T1059.005 Visual Basic

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a known technique for executing malicious code upon opening. Heuristics indicate the use of dangerous formula APIs, and ClamAV detection identifies it as an Emotet downloader. The macro likely downloads and executes a second-stage 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