Office (OOXML) / .XLSX malware analysis — malicious · 126a5bb68199565e

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: e41a1c0d096bd6a658cf781f40ac33c1 SHA-1: ab258088573133508ff188269a94b039ca1b7473 SHA-256: 126a5bb68199565e38f184a8269eb5dc52dab0db837aa1a5fddacc52ac448349

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel spreadsheet containing Excel 4.0 macros, which are known to be used for malicious purposes. The heuristic firing indicates the presence of these macros, which can be used to execute arbitrary commands. The macros themselves were truncated, preventing a full analysis of their specific actions, but the presence of XLM macros strongly suggests an attempt to download and execute a second-stage payload.

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` `31b0a945ae5de37ce6d68b00d975fa2b49370857823c73c05b0422404744c819`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	625211 bytes

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