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

Static analysis result for SHA-256 425eaf86bd759267…

MALICIOUS

Office (OOXML) / .XLSX

216.7 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 7382711078d2654c7d2ad8172bf93b9d SHA-1: 23f2ea3969736e2ead1447cd6d8a5a933f1fe6b2 SHA-256: 425eaf86bd759267d4c4a4715f4f1465e6abca73d0b042d3836fa92a664a63d2
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell T1204.002 Malicious File T1105 Ingress Tool Transfer

This XLSX file contains Excel 4.0 macros, which are known for their ability to download and execute payloads. The macros utilize dangerous XLM functions like FORMULA and REGISTER to call Win32 APIs, facilitating the download of a second-stage payload from the provided URLs. The presence of hidden worksheets further suggests an attempt to conceal malicious activity.

Heuristics 7

  • Excel 4.0 macro sheet (3 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: FORMULA, GOTO, HALT, REGISTER, EXEC 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.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present
  • 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 3 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://45.144.30.80/44313,6048108796.dat
    • http://45.90.59.97/44313,6048108796.dat
    • http://185.212.128.51/44313,6048108796.dat
    • http://185.212.128.51/
    • http://45.144.30.80/
    • http://45.90.59.97/
    • 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
    • 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/spreadsheetml/2016/revision6

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
125e232ed61153a54047fc42bf831a7a5df16598df76aff16860bf28521d2ade
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2760 bytes
vbaProject_00.bin
af57cc08826aca155a5cd6cb3cbe301be728347581c90b0f91c6ed775ade988d
vba-project OOXML VBA project: xl/vbaProject.bin 13312 bytes
xlm_sheet_00.xml
085884862ae3025b15b1ff3b63f007d710179f37582cb4d8fd0cdb284cfa344c
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 4302 bytes
xlm_sheet_01.xml
9ca9d23ba3a5b04b35f5c4332df1ce68c0463c9fa42327aa2f7cde6c21f3e64c
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 2121 bytes
xlm_sheet_02.xml
5e80fd069ac35c5e39918d8dfaaf0ba77875f57b487bcfcc5d8bc7d346806551
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.xml 1832 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).