I am having the strangest problem that I nor other people I have asked has ever seen before.

My computer seems to be putting passwords on all the user accounts on it's own. I have no idea what the password is because I have never set this computer up to have passwords.

This doesn't happen all the time and it only seems to happen when the computer is idling. I have been noticing it happening more often recently than before.

The funny thing is the solution to removing the password is just restarting the computer.

Could this be some kind of malware or glitch and has anyone heard of this happening before?