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

Static analysis result for SHA-256 61de811b093b19e6…

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-27 11:44:16 Authoring application: Microsoft Excel
MD5: 8166cf2c0bf75c321de85f29445d7be2 SHA-1: cdae490d55970a5c793738f21431c8088819eb7a SHA-256: 61de811b093b19e6c0d0ac66a2923110bd3c4aaa7705694141ab4c40888b26b9
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 defined name, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. While the exact payload is not discernible from the provided evidence, the mechanism points to a macro-based execution of 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
d4ef1b2f61a0ceea2f85be5f6c7e84f68363ded20f0be4a065df5f57bd85bdb6		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6578 bytes

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