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

Static analysis result for SHA-256 1feb0d9f5e05f98c…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: c77e08e83ffb9de2e924ca8c0286d2f5 SHA-1: 1673dd3f85cdcd24ad76ab06eae9d073c059a77f SHA-256: 1feb0d9f5e05f98c241efa48cff42ed774d4fe759e7f487aa6645ed746eab0c7
160 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open macro that utilizes dangerous functions like RUN. This indicates the macro is designed to execute arbitrary code. The presence of ShellExecute API references further supports this, suggesting the macro attempts to download and execute a second-stage payload from the provided URLs. The ClamAV detection name 'Doc.Downloader' reinforces this downloader behavior.

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://ump.edu.pe/ds/261120.gif
    • https://ump.edu.pe/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
56d07016068e454a1af96b6cee33e5364bc7ae97582ff73833a2c41ba0035917
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6675 bytes