Office (OOXML) / .XLSX malware analysis — malicious · ffcd1662b626cebc

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: debc139cf96bf3c38f8b665b1a130957 SHA-1: 59b91c02041f391793f1099d6e72cdfcf257d2c2 SHA-256: ffcd1662b626cebcd906d25a32418e2f60016d9c32860501d5aa00b70843e5e5

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The sample is an Excel file containing a macro sheet, indicated by the OOXML_XLM_MACROSHEET heuristic. The extracted macro content is heavily truncated and obfuscated, making it impossible to determine the exact payload or execution flow. However, the presence of Excel 4.0 macros strongly suggests an intent to execute arbitrary commands.

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` `484d8d159c17b5014fc35483d7831b530231f15cf9012072a33b5461a0f250f1`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	269630 bytes

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