Failed Sudo Attempts - Use This Query
Who wishes they had sudo access? Who has sudo access but always fat-fingers their password? This query will help you answer these burning questions and maybe find somebody doing something sneaky.
The Query:
tag=syslog words authentication failure | syslog Appname==sudo Message Hostname | regex -e Message "authentication failure; (?P<kv>.+)" | kv -e kv -sep = user | stats count by user Hostname | table user Hostname count

(Image credit: xkcd)