Office (OOXML) / .XLSX malware analysis — malicious · cb53bf4394e7f775

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: b6c09b88eeb411e648f688e7ca6a1ca9 SHA-1: da6a58fbb01118bf77842f75cb217c3cf33ded2f SHA-256: cb53bf4394e7f77534ca8bfa1039fc76c50a54be4dce411926dbb594a1a55c52

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic

The file is an Excel document containing Excel 4.0 macros, indicated by the OOXML_XLM_MACROSHEET heuristic. These macros are known to be used for executing arbitrary commands, often to download and run further malicious payloads. The macro content itself is heavily truncated and obfuscated, preventing a more detailed analysis of its specific actions or the reconstruction of any URLs or commands. Therefore, the exact attack pattern and family remain unclear.

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` `3b515b91ec0aa122d49959d456d36c3492688a28aea4dcfe82e4831bbd3a499a`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	7964 bytes

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