mchain
2
Since you did a static scan of your archival files, this detection is related to a PUP or PUA detection.
Not to worry about.
A part of a file detected would have had elements where unwanted advertising or scumware may have been present.
If you wish to save a file for later retrieval use quarantine instead of fix automatically to avoid deletion.
A program to minimize free/PUP or PUA installs: https://unchecky.com/