Virus action taken left alone

Hi,

In one of my system, virus log WS.Reputation.1 virus has been detected and the action mentioned as left alone.. what is that means and in secondary action it is mentioned as the file was allowed by user.

what is the WS.Reputation.1 means? what is the impact? what it will do exactly means behavior of that virus.

And what is meant by left alone.

We got some serious network issue in our side, which we are suspecting is bcoz of this system.