Office (OOXML) / .XLSX malware analysis — malicious · a3b638a28d674b86

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: f9f342620b7fab2fe2784438961a4cd4 SHA-1: 5fe70fcc7d47b0b092fa516524ec6b68fc656c66 SHA-256: a3b638a28d674b86b6c2873749e09ca75d3612ed46695ed1d5084df1f45fea35

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The sample is an Excel file containing Excel 4.0 macros. The heuristics indicate the presence of a macro sheet, which is often used to execute arbitrary commands. The script content is heavily truncated and obfuscated, preventing a detailed analysis of its specific actions or payload. However, the presence of the macro sheet itself is a strong indicator of malicious intent, likely for command execution.

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.