How to detect and block ip stresser traffic on your network?

IP stresser services such as booter or DDoS-for-hire services are a way for malicious actors to carry out distributed denial-of-service (DDoS) attacks. By paying a subscription fee, anyone easily rent access to an IP stresser service’s firepower to overwhelm websites and networks with junk traffic.

Top signs of an ip stresser attack

Detecting the fingerprints of an IP stresser-powered DDoS attack requires close monitoring and analysis of your network traffic.

  • Spike in bandwidth – One of the first red flags will be your WAN bandwidth maxing out, indicating a volumetric flood sustained high throughput point to an IP stresser.
  • High volume of UDP traffic – Most IP stresser-driven DDoS attacks leverage barrages of UDP packets to overwhelm targets. A UDP packet flood is a strong sign.
  • Packets from random source IPsWhat Is an IP Booter? Because IP stressers leverage large pools of compromised devices; you’ll see traffic sourced from thousands of different IP addresses.
  • High DNS errors – For DNS amplification attacks, you’ll notice anomalously high DNS query volumes and responses containing large payloads.
  • Targeting of network infrastructure – Aimed at routers, firewalls, and other infrastructure to disrupt connectivity. This contrasts with application-layer attacks.
  • Repeated attack patterns – Sophisticated attackers will frequently change IP stressers to vary fingerprints, but repeated spikes indicate DDoS.

Seeing one or more of these indicators should raise your suspicion. Analyzing traffic patterns confirms an IP stresser attack.

Identifying the ip stresser source

Pinpointing the IP stresser service source powering a DDoS attack allows you to block it at the source.

– Packet capture analysis – Packet captures from your perimeter firewalls and routers can trace attack traffic back to the originating IP stresser infrastructure.

  1. Review server access logs – Logs from web servers, email gateways, and other systems being hit often record the original IP address of the attacker.
  2. IP geolocation – Use a geolocation service to map IPs back to their source countries. Most IP stressers originate from a handful of overseas hosting providers.
  3. BGP monitors – Monitor border gateway protocol routing announcements, which often advertise IP stresser server subnets.
  4. DNS lookups – Reverse DNS lookups on attacking IPs can reveal domains linked to booter services.
  5. Edge sandboxing – Detonate suspicious files in sandboxes to identify IP stresser C2 infrastructure.

Once the IP source is identified, you can block it at your firewalls and alert your ISP to potentially blackhole traffic. But often IP stressers rotate addresses, requiring additional protective steps.

Ongoing protection monitoring 

With attackers continually evolving techniques, ongoing monitoring and tuning is critical after implementing protections:

  • Review traffic patterns – Continuously analyze bandwidth usage, connection rates, packets per second and other metrics for abnormalities.
  • Tune tools – Adjust flood protection thresholds, connection limits and reputation scores based on learnings to improve accuracy.
  • Expand visibility – Add network sensors and traffic capture capabilities closer to infrastructure edges to improve detection.
  • Update baselines – Re-baseline normal network conditions periodically to account for changes.
  • Assess service providers – Regularly review the effectiveness of ISPs, scrubbing centers and DDoS protection vendors.
  • Test defenses – Conduct controlled DDoS simulations to verify protections are working properly.

Keeping your defenses up-to-date and tuned is just as essential as initial deployment for blocking IP stresser attacks long-term.