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

Static analysis result for SHA-256 c7e33e2aa70e4550…

MALICIOUS

Office (OLE) / .XLSX

329.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: b4181faf722171869d03e0befcccc9ed SHA-1: c7f7b06d652e29bafe3702691717935851ef09c2 SHA-256: c7e33e2aa70e45505b5639cc27169f25ff5540ca8221ea9cf0e4b2c0a55ce67b
160 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open macro that utilizes dangerous functions like RUN. The heuristic firings indicate the use of ShellExecute, suggesting the execution of external commands or files. The embedded URL is likely used to download a second-stage payload. The ClamAV detection name 'Doc.Downloader' further supports this analysis.

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 http://i.sfu.edu.ph/ds/161120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
e17e7cc4a238aa7ef2e84a739a77bbc946bb2881b6aa82203097e9ab8210d20f
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6273 bytes