Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
Should be easy, and your card includes all the software you'd need to do it, although other stuff will do it better.
First off, if the audio is coming in through the line-in on the soundcard, all you should need to do is open up Creative Mediasource, and record the audio from the line-in. If you're using some other way of inputting the sound, simply change the source method, though "What U Hear" should be used only as a last resort, as it in my opinion creates a lower quality recording. Now, the software itself lets you record as an mp3, so you could do that, or record as a wave and use an mp3 compression program such as Creative Audio Converter, or LAME if you want good quality, to change the waves into mp3.