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

Static analysis result for SHA-256 05f169f9119060d1…

MALICIOUS

Office (OOXML) / .XLSM

109.5 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 756a6dca5aa7c3c09a366b4fbb6d98bf SHA-1: 490243764c6510b3d884f6fa20c8245ad325e986 SHA-256: 05f169f9119060d13e2fd468af1d82c7e7a56a64e6a7e31c92c49f1eae14a5ca
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel macro-enabled workbook (XLSM) utilizes Excel 4.0 macros, which are known for their ability to execute arbitrary commands. The heuristics indicate the use of dangerous XLM formula APIs like EXEC and CALL, which are used to download and execute payloads. The document body and extracted URLs point to external resources, likely for payload delivery. The script attempts to execute commands such as EXEC(Sheet2!AM34&"..\duron.bnm1",DllRegisterServer) and EXEC(Sheet2!AM34&"..\duron.bnm2",DllRegisterServer), suggesting a multi-stage download and execution process.

Heuristics 6

  • Excel 4.0 macro sheet (2 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, FORMULA, WORKBOOK.HIDE, CALL 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.
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 1 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction
  • 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 https://shapoorjipallonji.online/drms/ind.html
    • https://studio.joellemagazine.com/drms/ind.html
    • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
477aeccaaa162efd32bb8acf28c472f6c70359e46f59213b79e20f048af0f34f
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml 3528 bytes
xlm_sheet_01.xml
9f930289e13f67da399b0aeb5dc75db9b6d9febed2d1afb324c89cca03dce6a5
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 205645 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).