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

Static analysis result for SHA-256 e3982ad2f662dda0…

MALICIOUS

Office (OLE) / .XLS

41.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 166129744d312c6f620ba01a6b5eba99 SHA-1: fdddaac8c0b7cc78a57eb4b1f7b0bc194cc3d0d4 SHA-256: e3982ad2f662dda08f4e84a4875797c24e1f981b9f048cbc2b2269252c92b6f8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell

The file is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The macro sheet contains references to dangerous functions like RUN, suggesting it is designed to download and execute a second-stage payload. No specific family could be identified, but the technique is consistent with macro-based malware delivery.

Heuristics 3

  • 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.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
af05a6585fb3e8d2e95a498137b13f82ed2646447071ef8ada6a1050c823d012
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8115 bytes