Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 3e97f09fc53890ba…

MALICIOUS

Office (OLE) / .XLSX

106.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-03-29
MD5: 5b15f58c5dafced4214dacc04689585a SHA-1: 85ec91fc0c5045daed43fffb11599aa314197f97 SHA-256: 3e97f09fc53890ba2d5ae2539b5c8df372ed2506ed217d05ff2cf8899d15b8e6
262 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1059.003 Windows Command Shell

The file contains Excel 4.0 macros with an Auto_Open entry, which is a known technique for executing malicious code. The macros reconstruct and utilize six distinct URLs to download and execute a second-stage payload. ClamAV detection confirms this as Emotet, a downloader family. The use of `regsvr32.exe` and the reconstructed URLs strongly indicate a downloader functionality.

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-b2cbc93e36c0c13e-9950560-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-b2cbc93e36c0c13e-9950560-0
  • 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://dougveeder.com/cgi-bin/xJ91ZttGRioQ7IUL/
    • https://e-fistik.com/ajax/PnA23/
    • http://dsinformaticos.com/_private/f36Yl/
    • http://dstny.net/cgi-bin/POqJKcxiIzRb/
    • http://fakecity.net/cache/XtIzhyLEoLI7/
    • http://fayeschmidt.com/cgi-bin/Q8pj6/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
42fcced62e1b0500e019d401d9861bc8ead898ce0c99e4725ba96347a4a0e47e		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6551 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.