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

Static analysis result for SHA-256 e29edb94b3c20ff3…

MALICIOUS

Office (OOXML) / .XLSX

72.3 KB Created: 2021-10-27 10:31:49 UTC Authoring application: Microsoft Excel 12.0000
MD5: b7ace0179867e834b8113d2b2d6b8bc2 SHA-1: 2e2f8939fc0d9ec04db2ab7e7e2605f6e7f1a610 SHA-256: e29edb94b3c20ff3d43c1b9911520e0d1d333c9cf3d4ac1c0ebe12c3d0a0c84f
60 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The critical heuristic firing indicates the presence of Excel 4.0 macros within the XLSX file. The extracted macro content, though partially truncated and obfuscated, reveals a path construction that strongly suggests the execution of a file named 'excel.rtf' from the 'C:\ProgramData\' directory. This points to a macro-based execution of a secondary 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
25c1416efc2416dbd455f15e0d6781604a1ec536359452041ab8da6f42686259		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 108012 bytes

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