Found the error Not allowed to load local resource: file:///etc/passwd
while looking at infosec.pub’s communities page. There’s a community called “ignore me” that adds a few image tags trying to steal your passwd file.
You have to be extremely poorly configured for this to work, but the red flags you see should keep you on your toes for the red flags you don’t.
Also generally the actual password (or rather its hash) is stored in /etc/shadow on most systems from the past 20 odd years.