Grand Duchy of Luxembourg

DDoS Attack

How to detect - the signs to watch out for

  • The problem is that there are no tell-tale signs or warnings.
  • You can monitor your traffic and server load, but usually, customer complaints show that something went wrong.
  • In the server logs, you can see a spike in traffic.
  • Your server responds with a 503-error message due to service outages.
  • The TTL (time to live) on a ping request times out.
  • If you use the same connection internally, your employees will notice slowness.

How to react - the reflexes to adopt

  • The best reaction is prevention.
  • Schedule alerts to a 503 event in the Event Viewer to send a notification e-mail to the system administrators.
  • Automate ping alerts: if the ping time becomes too long or times out, the service sends an alert to your team, so they can start using mitigation techniques and troubleshoot the issue.
  • Use log management systems, so you can identify an ongoing attack and send alerts to your administrators.
  • Try to filter out the malicious traffic requests by setting alerts based on a combination of events and traffic spikes.
  • Work with the company you bought your domain from and change TTL to 1 hour.
  • Move your site to a DDoS mitigations service.
  • Follow CIRCL’s recommendations to mitigate the attack (see below).