topic Re: Regex not working as expected in Splunk Search

Regex not working as expected

cyber_castle — Mon, 02 Sep 2019 22:40:16 GMT

For one of the Security usecase, we need to extract Group Memberships from the Domain. The trickier part is some of the Group Memberships doesnt have domain name in front of it.

I am attaching the Regex link which is working fine on Regex101-

https://regex101.com/r/X2YAAd/1

but for some strange reasons, when i use the same regex on Splunk its not working.

This is to extract Group membership on EventCode=4627

Could anyone help me here..

Re: Regex not working as expected

skalliger — Tue, 03 Sep 2019 07:05:23 GMT

Always set the RegEx engine to Python. Also try to set (?ms) in front, that should do.

Skalli

Re: Regex not working as expected

KARANMALHOTRA — Tue, 03 Sep 2019 12:31:23 GMT

Can you elaborate what you mean by "same regex is not working on Splunk"?

One problem may be that you are not using any names for the groups, so Splunk does not know what to name the field.

Also, if you need multiple matches, try using the max_match option.

Re: Regex not working as expected

cyber_castle — Wed, 04 Sep 2019 12:35:13 GMT

Hello I have tried with the capturing group and still no luck

https://regex101.com/r/X2YAAd/2

Re: Regex not working as expected

cyber_castle — Wed, 04 Sep 2019 12:36:28 GMT

Ahh.. i have always used PCRE. When I have changed to python its blank.

Re: Regex not working as expected

skalliger — Wed, 04 Sep 2019 17:54:38 GMT

The https://regex101.com/r/X2YAAd/1 of your original post works for me when adding (?ms) at the beginning and using Python. Did you try that in Splunk?

Skalli