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

Static analysis result for SHA-256 7510b00f9f1c4405…

MALICIOUS

Office (OOXML) / .XLSM

92.6 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: dc9ce066c471b34cbf95e813214746c5 SHA-1: 4fe8cb46da0584561483ad26fd5d83258fdc4835 SHA-256: 7510b00f9f1c4405a79345d96614fef332cf1ee36c636b3301b11bac8cb6c9e0
182 Risk Score

Malware Insights

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

This XLSM file contains Excel 4.0 macros, including an Auto_Open defined name, which is a strong indicator of malicious intent. The macros utilize dangerous functions like CALL and EXEC to download and execute a second-stage payload from a list of embedded URLs. The presence of these functions and the embedded URLs strongly suggests a downloader or droppper functionality.

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: EXEC, HALT, CALL, FORMULA.FILL 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
b2aa95d3b3a02526f200b3d969c9988b4d5832e6c13ac8dcb3a1d9eb395b3574		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 213450 bytes

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