iCloud password multiple times at boot - app specific passwords

Since a clean install of Yosemite(but retrieved data from time machine), my MBP asks for the iCloud password multiple times at startup.

When I enter the password in one of the dialogs, I am asked to generate a app-specific password. But I can't even see for which app the password is needed.

I checked my login items, none of them will request the password and the amount of requests exceeds the amount of login items.

Is there any way to see which applications are asking for the password? Maybe in the logs? If so, please let me know where to look, because I couldn't find it in the logs.

Thanks in advance for your help.