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

Static analysis result for SHA-256 60a71e6de4c107f1…

MALICIOUS

Office (OOXML) / .XLSX

109.4 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 4870aa6d666016c3667317a492450607 SHA-1: f5b74a37c0d3e16026ed3b2f28d1cc7df4d77512 SHA-256: 60a71e6de4c107f1f2e7ddec59cc37e07a2a770f7635184202fb6d852c3a929e
190 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel document contains critical Excel 4.0 macros that utilize dangerous API functions like CALL and EXEC. The Auto_Open macro in the VBA project attempts to run code from a hidden sheet, which is a common technique for obfuscation. The macros are designed to download and execute a second-stage payload from one of the provided URLs, such as http://91.211.91.82/44313,6048108796.dat.

Heuristics 6

  • 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: HALT, GOTO, 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 a VBA project — VBA macros present
  • 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://91.211.91.82/44313,6048108796.dat
    • http://82.117.252.199/44313,6048108796.dat
    • http://45.138.157.43/44313,6048108796.dat
    • http://91.211.91.82/
    • http://82.117.252.199/
    • http://45.138.157.43/
    • 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
19626508773a68d544063e9cd47e5407816d3506d0c5df431dfadcc2ae560644		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 786 bytes
vbaProject_00.bin
199889e0394000a2e1581ef295e9f53a3c6d626d9f7063b3c9ef8cf8e3ca63c5		 vba-project OOXML VBA project: xl/vbaProject.bin 10240 bytes
xlm_sheet_00.xml
a3ff78ad476320d5df05f36d29827f0ccf7c95830338250c5be8e68dc7098191		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 4285 bytes
xlm_sheet_01.xml
a5fc80b1569128bd0323daacf4b0484b147d9d37755aacc26435ea011bd9f0cd		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 2111 bytes
xlm_sheet_02.xml
a6c079d2a564b952bdc7f60d49402489a374e91f07f8b51ef328523d2a650900		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.xml 1944 bytes

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