Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 f99eeea66e8ced80…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 690c2d9c095d526fe0e7ab42d4989e01 SHA-1: a22d81c806b11e434acb1e7f8f31caf88f6e3483 SHA-256: f99eeea66e8ced8079d6e3dca75f2f8c971d0fcd79f5d897a08e08e92e81391b
160 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically triggering the Auto_Open function with dangerous formulas like RUN. This indicates an attempt to execute arbitrary code. The presence of ShellExecute API calls further supports this, suggesting the macro is designed to download and execute a secondary payload from the provided URL. The ClamAV detection name 'Doc.Downloader' reinforces this downloader functionality.

Heuristics 5

  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • XLM Auto_Open with dangerous formula APIs high 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.
  • 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://zerones.biz/ds/261120.gif
    • https://zerones.biz/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
7fbdfe5319125c7a88728c7d99286583a9907fcc6c0161898412d727b081f128
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6676 bytes