The term “SL DDoS” refers to a specific type of Distributed Denial of Service (DDoS) attack that targets the DNS infrastructure by overwhelming the authoritative DNS servers with a high volume of malicious traffic. This attack is named after the initial domain label “SL” (i.e., `0x53 0x4C`) that is commonly used in the attack payloads.

Here’s an overview of how SL DDoS attacks typically work:

1. Exploiting vulnerability: Attackers identify vulnerable DNS resolvers or misconfigured DNS servers that can be used as amplifiers in the attack. These servers are often open resolvers or servers with recursive DNS functionality enabled.

2. Spoofing source IP addresses: Attackers spoof the source IP addresses of their attack packets to make it appear as if the traffic is originating from the target’s IP address. This technique helps in disguising the true source of the attack and makes it harder to mitigate.

3. Generating massive DNS queries: The attackers send a massive volume of DNS queries with the “SL” payload to the vulnerable DNS resolvers or misconfigured DNS servers. These queries are designed to elicit large responses from the servers, creating a significant amplification effect.

4. Overwhelming the target: The amplified responses from the DNS servers are directed towards the target’s IP address, flooding its network bandwidth and overwhelming its infrastructure. The target’s servers may struggle to handle the excessive traffic, resulting in service degradation or complete denial of service.

SL DDoS attacks exploit the vulnerabilities in the DNS infrastructure, taking advantage of open resolvers or servers with misconfigurations that amplify the attack traffic. These attacks can generate a substantial volume of traffic, causing significant disruption to the targeted systems.

To mitigate SL DDoS attacks, organizations should implement best practices for securing DNS infrastructure, including proper configuration of DNS servers, disabling open resolvers, implementing rate limiting, and deploying robust DDoS protection mechanisms such as traffic filtering and rate limiting on network devices. Working with network service providers and implementing traffic monitoring and analysis tools can also help detect and mitigate SL DDoS attacks effectively.