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

Static analysis result for SHA-256 c76e07aea8015555…

MALICIOUS

Office (OLE) / .XLSX

329.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: a9b82cdb967b487b19fb2d3e1254fe7c SHA-1: 8a32c49feb52501b9fb0cc146b35ad15356061e6 SHA-256: c76e07aea8015555f0ba723fd59bc69fa3eee20583e55760898cf028c7cae0bd
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File T1059.004 Scripting: PowerShell

The file contains Excel 4.0 macros, specifically an Auto_Open function that utilizes dangerous APIs like RUN. This indicates an attempt to execute arbitrary code. The presence of an embedded URL suggests a downloader functionality, likely to fetch and execute a second-stage payload. The ClamAV detection name 'Doc.Downloader.Docusign0521-9864805-0' further supports this conclusion.

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://btchs.com.br/ds/161120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
c7e4e7ed3c1ce4a0357cad7ea2d4765567912ff9637c55ef23ac64833b3a62a6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6274 bytes