Thanks: I scanned the zipped file a couple of different ways before tinkering with it.
Using different AV scanners is the absolute minimum amount of protection to downgrade the action from "suicidally reckless" to "pretty risky". I don't want to engage in fear mongering, it's just that running someone else's DLL requires a leap of faith that is orders of magnitude bigger than installing a software that you bought. There, you have at least the legal framework to sue for compensation if the vendor of the software violates your rights. "Someone" uploading a DLL to "some site" in order to "help people" could just as well be a nefarious scheme to install a backdoor on your computer, and there is practically zero risk involved for the perpetrator. He has no reputation to defend, he cannot be easily found (and even if you do, he's probably residing in a foreign country).
The majority of people probably mean no ill, but there are some who have a vested interest in cyber-criminal behavior who target private computer owners. They have the resources to seed poinson pills into web sites that are nominally made for the purpose of hosting software packages that may otherwise be hard to find. I'm just advocating for a realistic perspective of the massively divergent risk-reward ratios for uploaders and downloaders; downloaders are already psychologically vulnerable (they have a problem, and the file promises a solution).