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

Static analysis result for SHA-256 ed959c048dea9c77…

MALICIOUS

Office (OLE) / .XLSX

36.5 KB Created: 2020-11-25 10:42:25 Authoring application: Microsoft Excel
MD5: 7fe4e5806089c2f3a81f260cf0c14952 SHA-1: d784d407c39613f5383249b45da7a1277d5d29b5 SHA-256: ed959c048dea9c77370d2f062921ea4a43499db22f6610664435e59781682306
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical finding. The heuristics indicate the use of dangerous formula APIs, including the 'RUN' function, suggesting the macro is designed to execute arbitrary commands. This is a common technique for downloading and executing a second-stage payload.

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
60ede0841e184764e973b8299e6fad52450a95cb51697ca9f1198f98ea60db13		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6698 bytes

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