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

Static analysis result for SHA-256 d55b219cab698a03…

MALICIOUS

Office (OLE) / .XLS

36.0 KB Created: 2020-11-27 11:42:00 Authoring application: Microsoft Excel First seen: 2022-04-23
MD5: fafae91a23f2c375f613b5dd1ed7dbc9 SHA-1: f4701547a36a92965353c8c6ac16d28a798841df SHA-256: d55b219cab698a036e8043e2652923f7b9831ad543d486038e92cc1faf56c0d4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic 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 a reference to 'Auto_Open', suggesting it is designed to run automatically. This indicates a likely attack pattern of macro-based initial access and payload 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
812cb79bdb7051e1f908ca2472eaced0e1084eec6d268bbc30439d9c5159cc59		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6664 bytes

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