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

Static analysis result for SHA-256 6a02d741851302cd…

MALICIOUS

Office (OOXML) / .XLSM

109.5 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 1f17f0349121dc1e42edfbeaab647a39 SHA-1: 8c763517beefa370aad5e9d9a64593fbaa22d4df SHA-256: 6a02d741851302cd2bd0e9ee4a82c1dc70bd8a22d8a9e34cd3172991127c322e
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1105 Ingress Tool Transfer

This Excel file contains Excel 4.0 macros, which are known to be used for malicious purposes. The macros utilize dangerous functions like EXEC and FORMULA to download and execute a second-stage payload from the URLs https://immobiliareneri.casa/drms/ind.html and https://gidbasket.com/drms/ind.html. The specific macro commands found, such as EXEC(Sheet2!AM34&"..\duron.bnm1",DllRegisterServer), indicate an attempt to execute arbitrary code, likely a downloader or dropper.

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://immobiliareneri.casa/drms/ind.html
    • https://gidbasket.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
7d118572f5fe7d6ff43ed02ebd45ba65e8abef406e7a780baf6c364273fc6add
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml 3454 bytes
xlm_sheet_01.xml
fbe5e7dbb69c9673a292262e360301ab1ec7a303eb74e3af592196e67c71385f
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 205673 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).