Office (OOXML) / .XLSX malware analysis — malicious · 1d9299ca6494ea38

MALICIOUS

Office (OOXML) / .XLSX

77.8 KB Created: 2021-10-27 10:31:49 UTC Authoring application: Microsoft Excel 12.0000

MD5: 0f1d208f14588d32e416bc2ec977dd45 SHA-1: dc288d5be0d26317ffe25d661e453e1c285e7144 SHA-256: 1d9299ca6494ea38d568ed081637abfa3dc0e49fce1b37ac327b2f37a9103e44

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The sample is an Excel file containing Excel 4.0 macros, indicated by the OOXML_XLM_MACROSHEET heuristic. These macros are known to be used for executing arbitrary commands, often as a first stage for downloading and running further malicious payloads. The script content was truncated, preventing a more detailed analysis of its specific actions or IOCs.

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` `f92a71bd6118bb3270062ecc5b6d9496b56f1435670776500b905dd2b605204d`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	7875 bytes

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