For science, I will try to find one that is acceptable to share and post a before/after, or just the results of the comparison.
What I recall from my initial investigation was that the binary was completely different, but opening the image did not indicate any changes. Almost like it was converted from RGB to CMYK or something.
I went back and found that I was mistaken. JPG files that were altered were in fact completely unreadable.
In the confusion, I missed that JPGs with certain naming patterns were encrypted and others were left alone. I took two unrelated facts, 1) that plenty of images were readable, and 2) that plenty of images had binary differences, and put them together to arrive at a faulty conclusion. I am not going to be too hard on myself based on how that day was going for me.
IMG_????.jpg and presumably DSC?????.jpg were encrypted and other patterns were left alone. I presume this is to inflict damage as quickly as possible without getting bogged down encrypting stuff from "Temporary Internet Files" for hours.
I wonder if they'd improve their conversion rate by leaving behind a thumbnail to remind people of how much they liked their pictures that now risk being gone forever.
What I recall from my initial investigation was that the binary was completely different, but opening the image did not indicate any changes. Almost like it was converted from RGB to CMYK or something.