I'm not sure on what website u saw this, but it isn't very good...
Maybe there's really a dangerous Libcurl.dll around, but there's also a very useful Libcurl.dll which is not a spyware and which is the one I'm using.
It's open source, and you can download it from there :http://curl.haxx.se/
It's a library that allows to easily access Internet. I use it to load a page on managames.com to check if there's a new version available for download.
I guess you could use http://www.spybot.net
to scan the file on your PC, if you want to be sure it's not dangerous...