voyager/1.0 seems to be just another name for cfetch/1.0 (
http://adminter.net/User-Agent.aspx/cfetch). Both of them come from
38.113.234.180 and
38.113.234.181 IP addresses. I am not sure whether these bots follow robots.txt as I've banned their IP addresses. These bots have a bug and incorrectly interprets some of URLs.