base64_decode ... is this malicious?

base64_decode ... I ran EXPLOIT SCANNER and it says "Used by malicious scripts to decode previously obscured data/programs" amongst other things. I would hate to think I gave an entry point to a hacker. I rarely buy plugins unless i trust the source (such as here and Warrior Forums). Now I am a bit worried!

Can anyone enlighten me about this. I bought a plugin from Warrior Forums and this particular plugin, KSWP Pop Wizard, which had rave reviews, seems loaded with questionable code. This is part of what the scanner came up with (see attachments), the more "urgent" ones.

Should I be worried? OR is it regular code that has been caught up in the "sweep"?