Office (OOXML) / .XLSX malware analysis — malicious · 52b61c02a74823e7

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: 0c7961c9fdc17ba6a0028c93f8eeaaaf SHA-1: 435744589706428d8114d9a77c8ff42dba435db8 SHA-256: 52b61c02a74823e7c4796603c37506cc1fa258be5d6a54902c262f598b07472f

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The file is an Excel spreadsheet containing Excel 4.0 macros, as indicated by the OOXML_XLM_MACROSHEET heuristic. The embedded macro sheet, xlm_sheet_00.bin, is likely responsible for downloading and executing a secondary payload. The macro content is heavily obfuscated and truncated, preventing a more detailed analysis of its specific actions or the reconstruction of any URLs or commands. However, the presence of Excel 4.0 macros strongly suggests a malicious intent, typically for delivering further malware.

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` `1db918ae6c518f6b1c8c4ba73f6b8f2800893da04ab9ab30b64974b86e7a21c9`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	7154 bytes

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