Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 5ffa4cb3f7db82c5…

MALICIOUS

Office (OLE) / .XLSX

92.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2023-02-11
MD5: c8d86480cae889d55896e2642369a5f1 SHA-1: 5912e9a715533d5b9110daab4dbafe49236c8891 SHA-256: 5ffa4cb3f7db82c5db94ff5a288f132602383e285c9f110ba3b2eae848b2e946
322 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample contains Excel 4.0 macros with an Auto_Open entry, indicating automatic execution upon opening. Heuristics indicate the use of URLDownloadToFile and a dangerous formula API, suggesting the macro attempts to download and execute a payload. The presence of 'regsvr32.exe' in the document text further supports the execution of external code. ClamAV detection as 'Xls.Downloader.Emotet' strongly suggests the Emotet family.

Heuristics 8

  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • 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-ca2435d8af069a3f-9977227-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ca2435d8af069a3f-9977227-0
  • 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.
  • 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.
  • Suspicious extracted artifact medium 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.
  • 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://www.muyehuayi.com/cmp/8asA99KPsyA/v6lUsWbLen/
    • http://concivilpa.com.py/wp-admin/i3CQu9dzDrMW/
    • https://wijsneusmedia.nl/cgi-bin/kFB/
    • http://www.angloextrema.com.br/assets/oEt1yYckHKlnNIq/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
7c258a44cd7f0e2d8170fa63da398de30d9685da4d7a3701a6126835e4acc2ed		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 9282 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 shell/COM execution token(s).

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