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

Static analysis result for SHA-256 62c62445baac038a…

MALICIOUS

Office (OOXML) / .XLSM

86.8 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 14.0300
MD5: 582f356839a20c3f0b73cfa91fc3244c SHA-1: 98d983fe29226600e68179d71a8c954d50b0b20e SHA-256: 62c62445baac038ae0c462b1fd7a2b5a4b0a4fdd6929fa1c889e2b8ec3c06c9d
182 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, evidenced by the OOXML_XLM_MACROSHEET and OOXML_XLM_AUTOOPEN_DEFINEDNAME heuristics. The macros utilize dangerous functions like EXEC and CALL, which are used to construct and execute commands. Specifically, the EXEC function appears to assemble a command from various cell references, likely to download and execute a payload from one of the provided URLs. The presence of these functions and the embedded URLs strongly suggest a downloader or initial access mechanism.

Heuristics 4

  • 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: WORKBOOK.HIDE, EXEC, CALL, HALT, FORMULA 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.
  • 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://thersnyc.com/fxcS6exSJr0/04.html
    • https://justverify.online/ZKrubZZn5V/04.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
emf_00.emf
442eb38c1c88060cf62c1fd88f48f9b8961edd687fe9250cf42ff79baf20ccae
ooxml-emf OOXML EMF part: xl/media/image1.emf 296536 bytes
xlm_sheet_00.xml
e2d0c69c580969a640d565ee7f4c9f99c84cac5b5d64c997ece3e584778305c8
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1638 bytes
xlm_sheet_01.xml
8877d538d505af08b0c326ee597bc05eb27a221881758da594814f19457722a4
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 3709 bytes