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

Static analysis result for SHA-256 225a2a0b263e5694…

MALICIOUS

Office (OOXML) / .XLSM

109.5 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 07aa5788f23458d65f7a8dd863fa1388 SHA-1: f598a5f022590cb775d90b6f731c5486ba9a6bf6 SHA-256: 225a2a0b263e56943c9b52c6d9b224383b3309fcd3bd850b546a02ee16b7206e
208 Risk Score

Malware Insights

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

The sample is an XLSM file containing Excel 4.0 macros, indicated by the 'OOXML_XLM_MACROSHEET' and 'OOXML_XLM_AUTOOPEN_DEFINEDNAME' heuristics. The presence of dangerous XLM formula APIs like 'CALL' and 'EXEC' suggests the macros are designed to download and execute external content. The document body explicitly contains two URLs, which are likely the sources for this malicious content. The 'OOXML_XLM_DANGEROUS_FN' heuristic confirms the use of functions capable of executing arbitrary code.

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).