#include <StringConstants.au3> ; to declare the Constants of StringRegExp
#include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate
Local $sRegex = "(?i)(ATTEMPT\s+TO\s+ACCESS\s+DATABASE\s+)(\S+)\s+by\s+([\w.-]+)\s+(was\s+denied)"
Local $sString = "<182>Mar 27 09:38:55 4.3.2.1 [5439570:00311-46004] 03/11/2015 14:13:05 ATTEMPT TO ACCESS DATABASE mail/abc.nsf by USER was denied"
Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYFULLMATCH)
; Present the entire match result
_ArrayDisplay($aArray, "Result")
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm