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

Static analysis result for SHA-256 4f840662a0fb60ad…

MALICIOUS

Office (OOXML) / .XLSM

109.5 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: 1137908ab607eb8731755c04e0e625d2 SHA-1: 05f60f45e0560495a3fead4b39a4bb9794971689 SHA-256: 4f840662a0fb60ad86e0cdd4aeb38698948adad9b2e5a564fa635d8b123cc78c
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Service Control T1059.001 PowerShell T1204.002 Malicious File: User Execution: Malicious File

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 payloads. The document body contains URLs that are likely sources for these payloads. The macros are likely intended to download and execute a second-stage payload from one of the provided URLs.

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).