using System;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		string pattern = @"^(?!.*\bTest12\b).*?(\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2,}(?:,\d{3}\b)?).*\bCorrect\b.*$";
        string input = @"Line 1: 2019-01-22 15:36:141,023: [Test][123] INFORMATION - Testing: Correct Test12 ping
 
Line 2: 2019-01-22 15:36:141,023: [Test][124323] INFORMATION - Testing: Wrong Test12 ping
 
Line 3: 2019-01-22 15:36:141,023: [Test][12554363] INFORMATION - Testing: Correct Test ping
 
Line 4: 2019-01-22 15:36:141,023: [Test][6761213] INFORMATION - Testing: Wrong Test12 ping
 
Line 5: 2019-01-22 15:36:141,023: [Test][46543123] INFORMATION - Testing: Invalid Test ping
 
Line 6: 2019-01-22 15:36:141,023: [Test][887] INFORMATION - Testing: Correct Test ping";
        RegexOptions options = RegexOptions.Multiline;
 
        foreach (Match m in Regex.Matches(input, pattern, options))
        {
            Console.WriteLine(m.Groups[1]);
        }
	}
}

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