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

Static analysis result for SHA-256 71564fd0ada44b6b…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 6e76adec4583bd5a830faf2021f4e496 SHA-1: 9b2125e8dedae64a152d3c9e3fc88a7da40a1719 SHA-256: 71564fd0ada44b6baf2766eaa3e402a587760cf728496857587d7179286cd979
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel 4.0 macro-enabled workbook contains an Auto_Open macro that utilizes dangerous functions such as RUN and CALL. The script attempts to construct strings like 'Ke32' and 'CrylA' and then uses CALL to execute them, indicating it likely downloads and executes a second-stage payload. The embedded URL was also noted, further supporting a downloader pattern.

Heuristics 6

  • 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.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
  • 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