There should be a lot of information in correlated log entries.
At the very left of the threat log entry, you will see a magnifying glass icon. Click it and that will open the detailed log view. On the lower panel, you will see correlated log entries. You can see correlated traffic log entries, URL filtering log entries, and wildfire submissions as well as other possible entries. These other entries will exist if these additional features were properly configured to log an event.