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

Static analysis result for SHA-256 5bef7b39fe02eabe…

MALICIOUS

Office (OOXML) / .XLSM

217.6 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 6f203feba292f1322dae52e76dbf4ce4 SHA-1: 16cc7e295c03de2c28edab0c6dc939fc033a0d03 SHA-256: 5bef7b39fe02eabea2c0261275876217eb8cc2f1c861c1a7ffeba6c1b0769373
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

This XLSM file contains both VBA macros and Excel 4.0 (XLM) macros, with the Auto_Open VBA subroutine and dangerous XLM functions like CALL and REGISTER being present. The XLM macros are designed to call external functions, likely to download and execute a second-stage payload from the identified URLs. The presence of both macro types and the use of dangerous functions strongly indicate a malicious downloader.

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 a VBA project — 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://91.211.91.71/
    • http://190.14.37.252/44313,6048108796.dat
    • http://91.211.91.71/44313,6048108796.dat
    • http://185.82.218.30/44313,6048108796.dat
    • http://190.14.37.252/
    • http://185.82.218.30/
    • 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
590b0126ca8d1e7bd88af1d58b85b0c62ce22d8c6fa543f2326f7f6b9b0e0d64
vba-project OOXML VBA project: xl/vbaProject.bin 13312 bytes
xlm_sheet_00.xml
6d2c54826d9f8cfbc27ceceafde259a335d4f7ce95274c4c00b5379894a0c3cc
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 4413 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).