Attachment: HTML smuggling with RC4 decryption

type.inbound
and any(attachments,
        (
          .file_extension in~ ("html", "htm", "shtml", "dhtml")
          or .file_extension in~ $file_extensions_common_archives
          or .file_type == "html"
        )
        and any(file.explode(.),
                any(.scan.strings.strings, strings.ilike(., "*?[(?[?]+?[?])%256]*"))
        )
)