They are regular text files.
this allows the post image attachments to be rotated in UBB.threads 7.6 to 7.7.4. It was replaced in 7.7.5 by an entirely new image gallery package.libs/image.js
this is what processes images when users attach them to posts. it has been in all of the ubb.threads versions for over a decade.ubb_js/quickquote.js
this allows users to easily quote post content in their replies just by clicking on the "quote" button. it has been in all of the ubb.threads versions for over a decade.
Your antivirus software is reporting false positives.
What Is a False Positive? Sometimes, an overly strict antivirus may flag a file as malicious and report it. This is a case of a false positive, or the erroneous identification of legitimate software as malicious or infected.https://www.hellotech.com/blog/false-positive