Office (OOXML) / .XLSX malware analysis — malicious · 51b34eb567ede3e3

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: 7eba1a71d13f5ff17f56b41c6ca9fa64 SHA-1: d5e04f5eb381311659ffcfbca84bec0b1138432a SHA-256: 51b34eb567ede3e3f07bdda44434b9e29922a84c317535d661f70a648c70333b

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The file is an Excel 4.0 macro sheet, which is a known method for executing arbitrary commands. The macro sheet itself is heavily truncated and obfuscated, preventing a detailed analysis of its specific actions. However, the presence of Excel 4.0 macros strongly suggests an intent to run malicious code.

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` `119c23e81170822b1f6a191c83a3ddd5e9e7aa1af2424c20845b54cbfb4246aa`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	620353 bytes

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