I've always been skeptical of those online converter tools. Once it's uploaded, you don't know who might have a copy. If the contents of your document aren't personal then I suppose it's not a worry.
That's why I was hoping that someone would have a different solution - Perhaps an add on to Adobe DC Reader. However, many of the cracked versions of software out there are made to have back doors that can be exploited by the nasty crackers at a time of their choosing.