TA-log4shellregex
Log4Shell Regex Technology Add-On for Splunk
This is entirely the hard work of Karan Lyons from his GitHub Gist code (https://gist.github.com/karanlyons/8635587fd4fa5ddb4071cc44bb497ab6), which I've wrapped up into a custom search command for Splunk. We stand on the shoulders of giants.
Please see documentation here: https://github.com/doksu/TA-log4shellregex/wiki