How to configure nginx to block userAgent with '\' transfer character?

Question

As the title says, there is a useAgent:

"Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html\xA3\xA9"

Block the userAgent in nginx configuration, written as:

Mozilla/5.0\ \(compatible;\ Baiduspider/2.0;\ +http://www.baidu.com/search/spider.html\xA3\xA9

But it is invalid. The xA3xA9 behind it seems to have been automatically escaped.

How should I write to block this userAgent?

Answer 1

\\