When I reset my macbook pro, the password gets changed. I have Yosemite 10.10.3 and Apple phone support haven't been able to get to the bottom of it yet. They suggested I re-install the OS but i'd rather find out what this is first.
To get back in to my account, I followed the instructions here to run setup assistant, create a new admin account and change my password. I can then login to my account. When I reboot or logout though, the password gets changed again.
I assume it's malware of some kind, though it isn't being detected by Sophos or ClamAV. I have Littlesnitch and can't see any suspicious processes making network calls.
How can I track down what is doing this?