CREATE TABLE dbo.FailedLogin ( 
   EventID INT IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED, 
   EventDate DATETIME NOT NULL, 
   LoginName sysname NOT NULL, 
   ClientName NVARCHAR(255) NULL 
); 
GO 


CREATE TABLE #ErrorLog ( 
  LogDate DATETIME, 
  ProcessInfo NVARCHAR(255), 
  LogText NVARCHAR(MAX) 
); 
GO 

INSERT INTO #ErrorLog ( 
   [LogDate], 
   [ProcessInfo], 
   [LogText] 
)  
EXEC xp_readerrorlog 0, 1, 'Login Failed'; 

INSERT INTO dbo.FailedLogin 
(EventDate, LoginName, ClientName) 
SELECT LogDate,  
  SUBSTRING(LogText, CHARINDEX('''' , LogText) + 1, CHARINDEX('''', LogText, CHARINDEX('''' , LogText) + 1) - CHARINDEX('''' , LogText) - 1) AS LoginName, 
  SUBSTRING(LogText, CHARINDEX('[CLIENT', LogText) + 9, CHARINDEX(']', LogText) - CHARINDEX('[CLIENT', LogText) - 9)  AS ClientName 
FROM #ErrorLog 
WHERE ProcessInfo = 'Logon' 
  AND CHARINDEX('Login failed', LogText) > 0; 

DROP TABLE #ErrorLog; 
GO