Malicious Office (OOXML) / .XLSM — malware analysis report

Static analysis result for SHA-256 b9086ba7727c25f2…

MALICIOUS

Office (OOXML) / .XLSM

106.9 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: e06aca9c7e14506b09120d9d847cd6da SHA-1: d565f92a5c8bf32f9f5cb32ad19bb69cb38b7515 SHA-256: b9086ba7727c25f2a06ec552b6c5ea02c34e7ce77232d03bab51f85c558ed8a4
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

This Excel macro-enabled spreadsheet (XLSM) utilizes Excel 4.0 macros, specifically leveraging dangerous functions like CALL and EXEC. The embedded document body content contains URLs that are likely used to download and execute a second-stage payload. The presence of Auto_Open and the use of Win32 API calls via CALL/EXEC strongly indicate a malicious intent to compromise the user's system.

Heuristics 4

  • 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.
  • Excel 4.0 Auto_Open defined name critical OOXML_XLM_AUTOOPEN_DEFINEDNAME
    Workbook defines _xlnm.Auto_Open or _xlnm.Auto_Close while containing an XLM macro sheet. This is the OOXML/XLSB auto-execution shape for Excel 4.0 macros.
  • Dangerous XLM formula APIs: CALL, EXEC, FORMULA.FILL, HALT critical OOXML_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet uses formula APIs that call directly into Win32 (=CALL/=EXEC/=REGISTER/=FORMULA). These are the primitives used to download payloads, write files, and start processes from an XLM macro without invoking VBA.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/spreadsheetml/2006/main
    • http://schemas.microsoft.com/office/excel/2006/main
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
9cf577639483a84c18a4933d3e27f255a331eea77d6198cb6ba582a5fa65de0a		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 240381 bytes

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