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

Static analysis result for SHA-256 ccaf2d5b16ec4d2a…

MALICIOUS

Office (OOXML) / .XLSM

104.7 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 85f7950b0e6cceae52d306d928202d25 SHA-1: 7c5fdcb1409dc638c8efc28add1f51f657daefb5 SHA-256: ccaf2d5b16ec4d2af193cf63d9b2c58aabe5c0aacdf09ad92b18d2d96043a7c3
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Service Control T1204.002 Malicious File: Malicious File

The sample is an XLSM file containing Excel 4.0 macros. Heuristics indicate the use of dangerous functions like CALL and EXEC, which are commonly used to download and execute payloads. The document body contains a URL that is likely the source of the payload. The macros are designed to download and execute a second-stage payload from the embedded URL.

Heuristics 4

  • Excel 4.0 macro sheet (3 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, FORMULA.FILL, HALT, EXEC 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
8370a1e92b107cad91ec54d5d2d7e2416067b15c03d5df1c91be01a243e1ce47		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 16586 bytes
xlm_sheet_01.xml
7e08c20736cde2d39e3da7e17dd21bef03c2ce26a0942fbfac90c925df5bb0c9		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml 1023 bytes
xlm_sheet_02.xml
1d574875047613d4002c2621fc25a83f69a8a88701bce35c44925e78d9fa4338		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 209966 bytes

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