Only download from HTTPS-secure sites. Run any downloaded PDF through VirusTotal.com before opening. Use a dedicated PDF reader (like Adobe Acrobat or Foxit) with sandboxing enabled.
The Internet Archive is a non-profit digital library. Type into the search bar at archive.org . You will often find user-uploaded scans of automotive magazines that have fallen into the public domain or are preserved for research. Note: Not all MAXQ issues are here, but it is the single best legal source for vintage scans. maxq magazine pdf