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

Static analysis result for SHA-256 0693cdbf1d1d7879…

MALICIOUS

Office (OOXML) / .XLSM

84.2 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 8f98c44e523e108f3acf5fec794c8e4b SHA-1: 1076a4a12d78282d9f85c1e8219f4aeaa2e506c2 SHA-256: 0693cdbf1d1d787949a1f7250701d397f69a2ece3de5860324872ec2123a5eb3
182 Risk Score

Malware Insights

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

The file is an Excel macro-enabled spreadsheet (XLSM) containing Excel 4.0 macros. These macros utilize dangerous functions like CALL and EXEC, which are known to be used for downloading and executing arbitrary code. The macros construct and attempt to access several URLs, indicating a likely downloader or droppper functionality. The presence of these functions and the embedded URLs strongly suggest a malicious intent to fetch and run a secondary payload.

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
6bb1fa7b25c4a31dd2d66243f24bc2b4809a5ecf6b1ca9480c724b6e46bd7687
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 238359 bytes