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

Static analysis result for SHA-256 da973a93f8c9ba52…

MALICIOUS

Office (OOXML) / .XLSX

54.1 KB Created: 2021-10-27 10:31:49 UTC Authoring application: Microsoft Excel 12.0000
MD5: 8eec1faeae2f3882083937a07b1cff6e SHA-1: c9b3e4ef73c09e29dbae67f50928a143c2d82523 SHA-256: da973a93f8c9ba52fa472673c88187bc5d0622c756c660268410347fc7781dd3
60 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Service Utility

The sample is an Excel file containing Excel 4.0 macros, which is a strong indicator of malicious intent. The macro executes a WMIC command to create a file named 'excel.rtf' in the ProgramData directory. This suggests the macro is likely a dropper or initial execution mechanism for a second-stage payload.

Heuristics 1

  • Excel 4.0 macro sheet (1 sheet(s)) critical OOXML_XLM_MACROSHEET
    Spreadsheet contains an Excel 4.0 (XLM) macro sheet — XLM was a major Office malware vector during 2020-2022 and evaded many VBA-focused controls before Microsoft tightened XLM defaults. Even legitimate XLM use is rare in modern workbooks. The macro sheet is stored as XLSB/BIFF12 binary content, which many XML-only OOXML scanners miss.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin
802f4fcfad56f8ad1cf6e8375a61ae08ce69a69e831c4780c6bbe65ce76bc3f4		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 154369 bytes

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