DLL Files from DLL Download Sites May be Infected with Viruses
Since DLL download sites are not approved sources for DLL files and often have little if any contact information available, there is no guarantee that the DLL file you just downloaded is free from a virus infection. Assuming you have a good antivirus program, an infected DLL file might be quarantined as you download it but there is certainly no guarantee of that.
Take the safe route and simply avoid downloading DLL files from these DLL download sites. DLL Download Sites Could Host DLL Files That Could Compromise Your Computer's Security DLL files are like small, specialized programs that can be programmed to perform various actions automatically, even actions that open your computer up to hacking and other kinds of intrusions. DLL files like this do exist. While it's unlikely that you will search for one of these particular DLLs files to download and install, it is a risk you take when you install a DLL file in your system from a DLL download site.
Don't risk it - follow the advice in the previous several tips and acquire the DLL from its source, not from a "back alley" DLL dealer!