The host at this IP address is running a malware botnet controller which is being used to control infected computers (bots) around the globe using a trojan horse.
Malware botnet controller at 51.38.94.87 on port 443.
$ telnet 51.38.94.87 443
Trying 51.38.94.87…
Connected to 51.38.94.87.
Escape character is ‘^]’
Malicious domains observed at this IP address:
ad-postback.biz. 60 IN A 51.38.94.87
ad-storage.biz. 60 IN A 51.38.94.87