It is tempting to hunt for an file to save the $3-$4 a streaming service costs. However, the risks often outweigh the reward.

If you are a true cinephile, buy the official Blu-ray disc. A physical Blu-ray is a native 1080p source with a bitrate of 30-40 Mbps. An "Index Of" file is usually compressed to 5-10 Mbps. The Blu-ray will look and sound significantly better.