Office (OOXML) / .XLSX malware analysis — malicious · e880f31959ccaa82

MALICIOUS

Office (OOXML) / .XLSX

374.5 KB Created: 2021-08-16 09:36:27 UTC Authoring application: Microsoft Excel 12.0000

MD5: 9dc15b501b36602e1b926b83b8512b1f SHA-1: ed8e773d0c8f868336cd4d67c5e2b52882cdbe24 SHA-256: e880f31959ccaa8226bf362e61b13b8bf0503fb17a48b80180e55eb2ebb1743b

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The file is an Excel XLSX document containing an embedded Excel 4.0 macro sheet. The heuristic firing indicates the presence of this macro sheet, which is a common technique for executing malicious code. The macro content itself is heavily truncated and obfuscated, preventing a detailed analysis of its specific actions or payload delivery. Therefore, the exact attack pattern and IOCs cannot be definitively determined.

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` `fd0f857a6877e23e854550b97955c89d3b83650f30c0740351c110c37e0b8a51`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	646484 bytes

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