BrowserModifier:Win32/ShieldSoftCby is one of the member of Trojan family. And it is also as malicious as the other Trojan. It is more hideous virus, since it is hard to be detect for any other applications. It doesn’t make any sense to detect it with anti-virus programs because it will never directly occupy much resource. And that is why we should give some guides regarding how to deal with it.
If you could find out whether there is BrowserModifier:Win32/ShieldSoftCby on your PC or not, you can judge it from some signs. When you computer operates slowly and even can’t recover after you test it with normal speed-up application, you should doubt it that accordingly. And the other conspicuous sign is the change of your settings. And BrowserModifier:Win32/ShieldSoftCby will cause all your settings on your PC out of order. If you happen to find that your PC is disordering, you may have great chance to have Trojan inside.