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

Static analysis result for SHA-256 d47030ddef2e7b81…

MALICIOUS

Office (OLE) / .XLS

41.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: fae94d6d3d105f118e04beb72b0da588 SHA-1: e8c2e042224c086926856e0ac705958743c898d7 SHA-256: d47030ddef2e7b8143f4bf4d701996fa4fe45d966da70b49982d8cede6595f1a
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook. Static analysis detected the presence of an 'Auto_Open' defined name, which is a common technique for automatically executing malicious code upon opening the workbook. The critical heuristic firings indicate the use of dangerous formula APIs within the XLM macro, specifically 'RUN', suggesting the macro attempts to execute arbitrary commands. No specific malware family could be identified, but the execution of the 'Auto_Open' macro is the primary indicator of malicious intent.

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
2a69481f9e29b72803511fb15ff8573359ed885cd93b7a4a3bdf28545bc7e650
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8120 bytes