I only install applications from:

a) vendors I trust b) confident in their security, and c) couldn't write the software myself.

In the case of the Curse client I just wrote my own batch scripts and used cygwin. I could have just as easily done it in Python or AutoIt.

As I wrote the software I know there is virtually no chance for malware.

I can't be as certain about the Curse client. As far as I know it isn't open source.

Maybe I'm more paranoid than most about security but it could be because I know how easily most systems are compromised.

With Curse as a company, the bad times began when they started consolidating independent sites into "Gamepedia".