Office (OOXML) / .XLSX malware analysis — malicious · 18407ed7a38c9d5f

MALICIOUS

Office (OOXML) / .XLSX

124.8 KB Created: 2021-03-29 19:55:06 UTC Authoring application: Microsoft Excel 16.0300

MD5: b36df30dc509238422eb05955e181a9f SHA-1: 1ef372b04a2241ceb1edd7ac6b8db950ab72c013 SHA-256: 18407ed7a38c9d5f6c0b200234eaed581b416a639c3905116575b3945105e0ad

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. These macros are likely intended to download and execute a secondary payload, a common technique for initial compromise. The truncated script content prevents a more detailed analysis of the specific payload or its destination.

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.

Filename	Kind	Source	Size
`xlm_sheet_00.bin` `0d7587152bc0f528e5a96e63bf55d518f873054a6c56d73970556b76fed247db`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	94808 bytes

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