When a client contacts me regarding a virus on their computer system, I find out that it is usually due trying to install a Portable Document Format converter that they found for free on the Internet. The virus (actually malware) is either bundled in as an additional program and by the client skipping the custom installation, the malware will automatically get installed. The other times, the PDF converter is a fake program and the installer will place the virus from their online repo so that if the client’s AV program does a scan, it will show up as clean.
Below are a few PDF converter programs that I have personally tested so you have a few options to use on your system. Keep in mind, the programs will be safe but you must download from the official website to ensure that it is malware and not repackaged by an exploiter.