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

Static analysis result for SHA-256 8b616f36b9c8689a…

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-25 10:30:04 Authoring application: Microsoft Excel
MD5: 21f6b217fe80fce21369b6038a76a37b SHA-1: 7b504dbdb9d79613a14f38f2620b8d21cabee1c3 SHA-256: 8b616f36b9c8689a6fe4f2b4801f13bc0134e20292f5cf9a3ced6c434a1c1ff9
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 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates the workbook is designed to automatically execute code upon opening. The presence of dangerous formula APIs like RUN further confirms the malicious intent to execute arbitrary commands. While the specific commands are not fully visible due to truncation, the Auto_Open function is the primary mechanism for 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
480a87f0a4f97ce68c489944d5fe26ba62c074f4e257e4ce669586d5ed4f07c7		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6463 bytes

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