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

Static analysis result for SHA-256 14a3215e5013609f…

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-25 10:44:42 Authoring application: Microsoft Excel
MD5: fdc33c678b7e7a09151e53ea7c3afe14 SHA-1: b6bae1f5b3baf44c8c656b7eb8acdd5721413f1f SHA-256: 14a3215e5013609fedc78b9c4ac5410aadac3029138c17733ff8075cf55ac832
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a critical finding. This indicates the workbook is designed to automatically execute malicious code upon opening. The presence of dangerous formula APIs like RUN further supports the malicious intent, likely to download and execute 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
3f1ca3e0c7c08fc0430d51e9ff2939bd652221a4d468f992a5c689845ad5212b		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6513 bytes

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