topic Re: Regex Help Event ID 4720 in Cortex XDR Discussions

Regex Help Event ID 4720

NathanBradley — Wed, 11 Jan 2023 18:12:52 GMT

Im attempting to get out the email address listed as User Principal Name in a 4720 event ID

Any help or explanation would be appeeciated

dataset = xdr_data
| filter action_evtlog_event_id = 4720
| alter User_Name = arrayindex(regextract(action_evtlog_message, "New Account:\r\n.*\r\n.*Account Name:.*?(\w.*)\r\n"),0)
| alter Create_By = arrayindex(split(arrayindex(regextract(action_evtlog_message , "Account Name:\t\t.*\r\n"),0), ":"),1)
| alter New_Email = arrayindex(regextract(action_evtlog_message , "User Principal Name:\t.*"),2)
| fields agent_hostname, User_Name , Create_By , action_evtlog_event_id,New_Email, action_evtlog_message

Re: Regex Help Event ID 4720

bbucao — Wed, 11 Jan 2023 18:36:29 GMT

Hi NathanBradley,
I noticed for the arrayindex on the new_email field you have it set to 2, which would tell it to match on the third instance of the matched pattern. In my environment for event ID 4720 I only see one instance of the field "User Principle Name", so I would set the index value to 0 unless you are seeing something different for your events. Also as it stands, you are capturing the text "User Principle Name in addition to the value that would be in that field. Try replacing with the logic below.

| alter New_Email = arrayindex(regextract(action_evtlog_message , "User Principal Name:(\t.*)"),0).

Regards,
Ben

Re: Regex Help Event ID 4720

NathanBradley — Wed, 11 Jan 2023 18:39:11 GMT

Thanks, Yes that worked