XML : encoded xml data displayed as random string

I had a client inquire me about building an app base on their website data. Apparently they had another developer that finished only half of the job and they gave me the xml feed urls, but I don't understand a thing as It never encoutered to me to see an encoded xml. So after I open one of the xml urls in my browser I see a malformed xml and opening source (ctrl + u) the xml content is like:

  8cfd1b4669c426ee4b8ab9fcce3c0473b9a39190d0d7f48    

and it continues like this till the end. No xml tag at all just random string (encoded?)

  HTTP/1.1 200 OK  x-amz-id-2: KiUDxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx4=  x-amz-request-id: CEEXXXXXX75  Date: Tue, 01 Dec 2015 21:01:29 GMT  Last-Modified: Mon, 30 Nov 2015 21:32:48 GMT  ETag: "4a09xxxxxxxxxxxxxxxxxxxxx82b5a"  Accept-Ranges: bytes  Content-Type: application/xml  Content-Length: 6336  Connection: close  Server: AmazonS3    8cfd1b4669c42  ....  c6d0    

Here is the header and I don't see anything like Content-Encoding : gzip or Anything similiar.

Anyone might have an idea of what kind of encryption is this? May it bee bytecode java?

Thanks.