Is there way to check wordpress logs? Like what actions admin has performed etc?

You can use a plugin for this: try Stream or its competitors.

I don't think Wordpress has an event log, at least I've never heard of one or seen one. There is a login logger plugin, but it has to be installed and doesn't work retroactively.

In theory, it should be possible to get at least the IP address of the perpetrator from the normal Apache access logs, and searching it for all recent accesses to the /wp-admin folder. That is pretty cumbersome work, though.