I have an account(some space) on sever located at USA
Now When I logged on there and check its sequrity
it shows trozen horse active please clearify what it means .If it is virus activation sign then how I can remove it please suggest me.

a trojan... is a file which will let a remote controller, control your server.. i suggest you delete the file ASAP and change all your system passwords.. also, check logs to find when that file was installed.. and verify that there are no more copies of the file..

What type is it?
Contact me, I'd be more then happy to help