Attachment: HTML smuggling with embedded base64-encoded executable

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(.),
                (
                  .file_extension in~ ("html", "htm", "shtml", "dhtml")
                  or .flavors.mime == "text/plain"
                )
                and any(.flavors.yara, . == 'base64_pe')
        )
)