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

Static analysis result for SHA-256 90f48be7100a93a5…

MALICIOUS

Office (OOXML) / .XLSM

334.3 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: d27ac168b5642518471c6e94c894d9c1 SHA-1: 4a082ed1c969028aeafae7773ef86d35e680e4e0 SHA-256: 90f48be7100a93a5e5b241ccf8bd5de70fbb3566558926310219256f1013603e
230 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File T1071.001 Web Protocols

This Excel document contains Excel 4.0 macros, which are known to be used for malicious purposes. The Workbook_Open macro triggers the execution of these macros. The critical heuristic 'OOXML_XLM_DANGEROUS_FN' indicates the use of dangerous XLM formula APIs like REGISTER and GOTO, which can be used to download and execute payloads. The embedded URL http://162.248.225.122/0 is highly suspicious and likely serves as the source for the payload. The script attempts to download a second-stage payload from this URL.

Heuristics 8

  • 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.
  • Dangerous XLM formula APIs: REGISTER, GOTO, EXEC, 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.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present
  • External relationship medium OOXML_EXTERNAL_REL
    External target in xl/externalLinks/_rels/externalLink1.xml.rels: IC-Office-Work-Schedule-Template16
  • 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 7 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 http://162.248.225.122/0
    • http://schemas.openxmlformats.org/spreadsheetml/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
    • http://schemas.microsoft.com/office/spreadsheetml/2014/revision
    • http://schemas.microsoft.com/office/spreadsheetml/2015/revision2
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision3
    • http://schemas.microsoft.com/office/excel/2006/main
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision6

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
c0c60e346d4801111e046b4acb1d8144259c1bf12e21684870e5fea861d54208		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2415 bytes
vbaProject_00.bin
04b47f1f5ed86064c9415e567fc8caf9f34084918f788d60b8e2338bf5547f31		 vba-project OOXML VBA project: xl/vbaProject.bin 16896 bytes
xlm_sheet_00.xml
7e5c746ebcc9a11e2f40f27f1e7c7308e494b3570e0e5d40daf31200b16e41c7		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 2245 bytes
xlm_sheet_01.xml
4e31892eaff02827de62da833c17b8112bcc26252e18a89b1a8bf7faeeca8ae2		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml 1735 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).

Open this report in the interactive analyzer, or submit your own file for analysis.