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

Static analysis result for SHA-256 b6dcad4823cfb8de…

MALICIOUS

Office (OLE) / .XLSX

36.5 KB Created: 2020-11-25 10:40:55 Authoring application: Microsoft Excel
MD5: 4211d4e068d145fafa0418ee38109897 SHA-1: 1255da9dee4012e250703d67009fda2f51edef56 SHA-256: b6dcad4823cfb8de518e45fb877b58b51c911139944a5dcaeb07698de904717f
140 Risk Score

Malware Insights

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

The sample contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates the workbook is configured to automatically execute a macro when opened. The presence of dangerous formula APIs like RUN further confirms the malicious intent to execute arbitrary code. No specific malware family is identifiable from the provided evidence.

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
d0d64c22383f5c753f87768ed9bd5611d6b4d0c305096c04f8dc18c6d87c270f		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6731 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.