Ever notice how people always jump to the worst idea first? It happens with everything, not just computer files. Like when your neighbor's trash can is out for days, everyone assumes they're lazy, but maybe they got sick or had to travel fast. Or at work, if a report has a typo, people think you don't care, but it could just be a tired mistake. Finding a weird file is the same, it might be from an old program or a simple error. Our brains just go to bad stuff before checking the simple answers.
What if assuming the worst is just our brain's way of being careful? In @susan597's trash can case, thinking it's laziness could make you check on a neighbor who really needs help. Sometimes that bad first idea is a useful alarm bell.