Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 bfc04f3644ea1ce2…

MALICIOUS

Office (OLE) / .XLS

47.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-04-22
MD5: 36b0f3d5e31df279ae732bfc2e754e2b SHA-1: 5cdbaecc65daea905283bfd5b020d1d54c5b197e SHA-256: bfc04f3644ea1ce23559f600068f0b0fde35fbc6936e23e4b9431ac3782beff3
202 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File: User Execution: Malicious File

The sample is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro that utilizes dangerous functions, specifically the RUN function, which is commonly used to download and execute payloads. The extracted URLs are likely sources for this second-stage malware. ClamAV detection further supports the malicious classification, identifying it as a downloader associated with Emotet.

Heuristics 5

  • 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: Doc.Downloader.Emotet04222-9946520-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Emotet04222-9946520-0
  • 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://www.escueladecinemza.com.ar/_installation/IBlj/
    • http://counteract.com.br/wp-admin/WWcACJFy3Yn/
    • http://dancefox24.de/templates/owT/
    • https://ciencias-exactas.com.ar/old/Bupubz1trh/
    • https://creemo.pl/wp-admin/0uDUHJ4KVAw/
    • http://focusmedica.in/fmlib/TYiQdcEj9FW0/�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
2670f09984c9f89e0c31dbfd71e019d5945a5ba86b2e4e522615b22d445dd7f0
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8122 bytes