Office (OOXML) / .XLSX malware analysis — malicious · 8aed942baf1f581a

MALICIOUS

Office (OOXML) / .XLSX

114.2 KB Created: 2021-03-29 19:55:34 UTC Authoring application: Microsoft Excel 16.0300

MD5: 0937815fa4b07374d68ba6e7644416e1 SHA-1: 880e1d91ae81a4e0414c307496b1ca9caa48c2f5 SHA-256: 8aed942baf1f581a31e9533622b6779a919de5efca0a72e817fefe88f5abc61f

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The sample is an Excel file containing a single Excel 4.0 macro sheet. The heuristic firing indicates the presence of these macros, which are often used for malicious purposes. The macro content is heavily truncated and obfuscated, preventing a detailed analysis of its specific actions, but the presence of XLM macros strongly suggests a downloader or initial execution stage. Due to the obfuscation and truncation, the exact payload and delivery mechanism cannot be determined.

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` `ff6807feee9531b59da3dd46d684897e9069798b0151f01d306dab9ce09988cf`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	95545 bytes

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