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

Static analysis result for SHA-256 d694d77a08a26a56…

MALICIOUS

Office (OOXML) / .XLSX

84.9 KB
MD5: a334d1e99f7a27019204873c965da223 SHA-1: 8d4917bf445bb9ac4bb9054fbc2b06fa5c06e14f SHA-256: d694d77a08a26a5606d32d83746e3aa2a32325e3c41b01c66f1f625b843bcc93
190 Risk Score

Malware Insights

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

This file contains Excel 4.0 macro sheets that utilize dangerous functions like FORMULA, which can be used to execute arbitrary code. The specific formulas appear to be concatenating strings to form commands or URLs, likely for downloading and executing a second-stage payload. The ClamAV detection further supports its malicious nature.

Heuristics 5

  • Excel 4.0 macro sheet (3 sheet(s)) critical OOXML_XLM_MACROSHEET
    Malformed OOXML local headers contain an Excel 4.0 (XLM) macro sheet. XLM was a major Office malware vector during 2020-2022 and is rarely used in modern legitimate workbooks.
  • Dangerous XLM formula APIs: FORMULA critical OOXML_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet uses formula APIs that call directly into Win32 (=CALL/=EXEC/=REGISTER/=FORMULA).
  • ClamAV: Win.Malware.Agent-9983616-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Malware.Agent-9983616-0
  • Malformed OOXML package with recoverable local headers low OOXML_MALFORMED_ZIP_LOCAL_HEADERS
    The OOXML ZIP central directory is invalid or missing, but local file headers expose a recoverable Office package. This can create parser divergence between tolerant Office/ZIP readers and scanners that rely only on the central directory.
  • 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://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
xlm_sheet_08.xml
5a62a357cb895c98dc30b4c4c5c056eac8ac1b92bc088a5bcf20517cbcd838f8		 xlm-macrosheet Malformed OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 3434 bytes
xlm_sheet_09.xml
c70a51acb5791492ef3f1e96d2217abba4360bc0964fdbbf0b281da430450073		 xlm-macrosheet Malformed OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 908 bytes
xlm_sheet_10.xml
84b5606b26315521210c94dce2556ab11c1d4148efb57521cf114d2065ef725b		 xlm-macrosheet Malformed OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 905 bytes

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