Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 5413887853b33e96…

MALICIOUS

Office (OLE) / .XLS

247.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: dae5b066e1344033a1e81739b1241d28 SHA-1: ee9e2fd1d1a87fc1e59b489fba5dadc8102b4b0f SHA-256: 5413887853b33e96e40e00c04cbe2261ccd53894ff142273e4fd8d8696555475
262 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File T1059.001 PowerShell

The sample contains Excel 4.0 macros, specifically an Auto_Open macro that utilizes dangerous formula APIs like RUN. The macros reconstruct and reference three URLs which are likely used to download and execute a second-stage payload. ClamAV detection confirms this behavior, identifying it as an Emotet downloader.

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 (3 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-MSOLE2-af43432fbcb8603c-9980047-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-MSOLE2-af43432fbcb8603c-9980047-0
  • 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 https://dostirealty.co/P9kjs85EJB/yy1.html
    • https://go.iscpelsalvador.org/hxIi071xf/yy2.html
    • https://system.sevenseriesmlm.com/AGsxCCeHHpI0/yy3.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
9f390265425713d6b44ef5f4ea4e0e5bb0aa5d8ed7f7161e7e0fe955bb4f5fea
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 11933 bytes