Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 1bbd0e2ecf37a657…

MALICIOUS

Office (OLE) / .XLS

126.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-03-29
MD5: 2094a10e5b5df5f70028e3c985ec929d SHA-1: b74662cfc6e25d8b40bd30ba02522052d0032da7 SHA-256: 1bbd0e2ecf37a657d22d4de7cbf17df6f136d1b4187f47bce83e59af9d57da3e
262 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for Emotet. The macros reconstruct and attempt to download payloads from multiple URLs. The presence of 'regsvr32.exe' in the document body suggests it may be used to execute the downloaded payload. ClamAV also detected this as Emotet.

Heuristics 6

  • 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.
  • URL reconstructed from XLM cell array (6 URLs) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://drvishalchestclinic.com/wp-includes/SqqCZQ6y2uyFF/
    • http://funestotal.com/5aclo1em/21U/
    • http://g-wizcomputers.com/party/61W0ovBu86/
    • http://primefind.com/1mall-uk/h5/
    • http://la-csi.com/mt-admin/BB7/
    • https://pancook.com/newsite/H6xxeLefX1I2vgJFM1Y/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
baa385ee141091e506d4fc8952e60f349e2a144300202c59dbc3e03ea3f9b493
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6541 bytes