[CentOS] invalid mirror .host-engine.com

Hello,

how can I prevent of using these mirrors?

# yum clean all
Loaded plugins: fastestmirror, security
Cleaning repos: base extras updates
Cleaning up Everything
Cleaning up list of fastest mirrors
# yum update
Loaded plugins: fastestmirror, security
Setting up Update Process
Determining fastest mirrors
  * base: centos.den.host-engine.com
  * extras: centos.den.host-engine.com
  * updates: centos.den.host-engine.com
http://centos.den.host-engine.com/6/os/x86_64/repodata/repomd.xml: 
[Errno 12] Timeout on 
http://centos.den.host-engine.com/6/os/x86_64/repodata/repomd.xml: (28, 
'Operation too slow. Less than 1 bytes/sec transfered the last 30 seconds')
Trying other mirror.
base                                                                         
| 3.7 kB     00:00
http://centos.den.host-engine.com/6/extras/x86_64/repodata/repomd.xml: 
[Errno 12] Timeout on 
http://centos.den.host-engine.com/6/extras/x86_64/repodata/repomd.xml: 
(28, 'Operation too slow. Less than 1 bytes/sec transfered the last 30 
seconds')
Trying other mirror.
extras                                                                       
| 3.4 kB     00:00
http://centos.den.host-engine.com/6/updates/x86_64/repodata/repomd.xml: 
[Errno 12] Timeout on 
http://centos.den.host-engine.com/6/updates/x86_64/repodata/repomd.xml: 
(28, 'Operation too slow. Less than 1 bytes/sec transfered the last 30 
seconds')
Trying other mirror.

is there a way of setting up a DNS ZONE where requests to this domain 
get somewhat like 'not exist'?

Thanks,
Walter