Log stash how to pattern match a phrase? Custom Regex?

Elastic Stack Logstash
1

New to Logstash and I have seen many items that discuss using defined patterns to parse logs but I have some ugly logs that don't fit a defined format. I need to do accomplish two things:

  1. Parse an ugly time stamp into its own field
  2. Look for a phrase to get the code value next to it.

Is it correct to use grok for this? I have only seen established patterns that don't fit my logs at all.

Input:
8:00:01:495/UTC(10/14/2016) ERROR ShieldWorker : Discovery_Shield:MAJ:Problems with call:org.springframework.web.client.HttpClientErrorException: 401 Unauthorized

I have attempted several iterations using the http://grokdebug.herokuapp.com/

2

Figured out the first part of the getting the ugly timestamp with:

%{TIME:time}%{GREEDYDATA:igrnore}%{DATE_US}

3 
%{TIME:time}%{GREEDYDATA:igrnore}%{DATE_US}

Faster, more exact, and extracts the date too:

%{TIME:time}/UTC\(%{DATE_US:date}\)

What else do you want to extract from the log message?