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

Static analysis result for SHA-256 930d2b391df777d9…

MALICIOUS

Office (OOXML) / .XLSM

105.5 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 69d15c03a2b016d881c36d96e39f64c5 SHA-1: 3e4dff46b8662e0dce6f8f110bd3112509823875 SHA-256: 930d2b391df777d93edd3f76990159b7fb4bdb7bab22a337e96d6e74c491f5e9
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell

The file is an Excel macro-enabled spreadsheet (XLSM) containing Excel 4.0 macros. Heuristics indicate the use of dangerous XLM functions like CALL and EXEC, which are commonly used to download and execute arbitrary code. The document body contains URLs that are likely used to fetch the secondary payload. The primary intent appears to be downloading and executing a malicious payload from the provided URLs.

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
1ac8164566eb69dad25e2fb55eafdc9b2a3eac004a1f0cc291930400a77c99df
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 230169 bytes