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

Static analysis result for SHA-256 53b3e2282bc83e0b…

MALICIOUS

Office (OOXML) / .XLSM

106.9 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 14a0b48a207a57e19913cfcbff9e4e26 SHA-1: 4fcac8ef351fa554e244ff0474617f906b35a669 SHA-256: 53b3e2282bc83e0b5fe60e544e88315fab96cac81f2f7771c12914a87142beeb
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link: User Execution: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell

The sample is an Excel macro-enabled spreadsheet (XLSM) containing Excel 4.0 macros. The macros utilize dangerous functions like CALL and EXEC, which are known primitives for downloading and executing payloads. The document body contains URLs that are likely used to fetch the second-stage payload. The presence of Auto_Open and the use of CALL/EXEC strongly indicate a downloader 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: 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.