If your APP application experiences a DDoS attack, it is crucial to take effective protection and emergency measures immediately. This website provides a detailed DDoS protection strategy, explaining how to prevent and mitigate attacks through traffic cleaning, CDN acceleration, firewall configuration, and other means. In addition, we also share how to respond quickly when an attack occurs, protect server and user data, and ensure business continuity. Click to learn more and master the best practices for defending against DDoS attacks!
1. What is a DDOS attack?
DDoS attacks, known as Distributed Denial of Service attacks, are a common and difficult attack to defend against. Attackers control a large number of botnets (puppets), send a large number of malicious requests to the target server, and consume the server's resources, thus forcing the server to go down.
For example, if you open a coffee shop now, the store is only 30 square meters. Normally, it can only accommodate 10 people. Suddenly, 1,000 people came today. These people are not real customers and are malicious. Your coffee shop exploded in an instant, completely unable to operate normally.
2. Types of DDOS attacks
Transport layer DDos attack:（Syn Flood、Ack Flood、UDP Flood、ICMP Flood、RstFlood）、DNS DDos攻击、连接型DDos攻击、Web应用层DDos攻击（HTTP Get Flood、HTTP Post Flood、CC）
Network layer attacks:(UDP reflection attack) - Transport layer attack (SYN Flood attack, connection number attack) - Session layer attack (SSL connection attack) - Application layer attack (DNS flood attack, HTTP flood attack (i.e. CC attack), game dummy attack)
| 攻击类型 | 说明 | 举例 |
|---|---|---|
| 网络层攻击 | 通过大流量拥塞被攻击者的网络带宽，导致被攻击者的业务无法正常响应客户访问。 | NTP Flood 攻击。 |
| 传输层攻击 | 通过占用服务器的连接池资源，达到拒绝服务的目的。 | SYN Flood 攻击、ACK Flood 攻击、ICMP Flood 攻击。 |
| 会话层攻击 | 通过占用服务器的 SSL 会话资源，达到拒绝服务的目的。 | SSL 连接攻击。 |
| 应用层攻击 | 通过占用服务器的应用处理资源，极大消耗服务器处理性能，达到拒绝服务的目的。 | HTTP Get Flood 攻击、HTTP Post Flood 攻击。 |
No matter what kind of attack, the goal is ultimately the same. Here are a few common types of descriptions:
- capacity
- agreement
- application
These three attack types are divided into many types, such as UDP, ICMP, IP, TCP, HTTP flood and other variants, as well as the current AI collaborative attack. The following CDN5 engineers will gradually explain the above types.
1. Capacity depletion attack
As the name implies, capacity consumption is the use of attacks to overload the target server and then crash, including UDP, CHARGEN, and ICMP.
- UDP flood attack
UDP protocol, send data packets to the target through the port. At present, the server will automatically process after receiving the data packet. Attackers attack the server in the network through the Internet Protocol Address and port embedded in the UDP data packet, and exhaust the target through a large number of requests. Common ones include: DNS, NTP, SSDP, IP Voice, p2p, SNMP, QOTD, STEAM, etc. Variants include, UDP fragmentation, UDP amplification attack (the protocol is usually SNMP, SSDP, NTP)
- CharGEN FLOOD
CharGEN protocol originated in 1983, and its purpose is to debug, measure, and request port 19 to send TCP or UDP requests to trigger. Attackers typically forge the Internet Protocol Address of the target server, run CharGEN networking devices to send requests, and then these devices respond to requests, bombarding with port 19. If the firewall does not block port 19, it will collapse.
- ICMP flood
The Internet Control Message Protocol consists of specific messages or operation commands sent between network devices, such as timestamp, timeout error, echo request ping command, etc. Attackers consume incoming and outgoing bandwidth by sending a large number of forged ping data packets. Now there are ICMP fragmentation attacks, which work similarly.
- app abuse
Attackers obtain high-traffic applications on legitimate servers and then redirect them to the target server. Since the data packets sent appear to be normal requests, most defense tools will misjudge and cause the server to fail.
3. The impact of the attack on the APP business:
- Direct losses: Service disruptions cause users to churn, transactions to fail, and brand trust to decline.
- Hidden risk: Attacks can mask other security threats such as data theft and ransomware implantation
- Compliance risk: Failure to respond in a timely manner may result in violations of data protection regulations (e.g. GDPR) and legal liability
If you are under a DDoS attackThe best way is to directly access the CDN5 Protection SDK.Consult now
4.APP how to defend against DDoS attacks
- architecture optimization
Adopting a distributed architecture, the business is divided into independent modules, such as user authentication, payment interfaces, etc., and deployed in different server clusters to avoid a single point of failure.
Purchasing Cloud as a Service Provider Elastic Resources: For example, using Google Cloud as a Service, elastic traffic dynamic quotas.
Close unwanted protocols and ports: Unwanted all-in close.
- Multi-layered defense
High anti-IP及高防CDN：购买CDN5高防IP或者高防CDN,通过节点分发，来应对攻击流量，清洗恶意请求。
Behavioral analysis engine: Utilizes AI algorithms to identify abnormal patterns. For example, 100 login requests from a single IP in 1 second can be judged as an attack
Rate Limit and Blacklist: Set limit_req_zone limit request frequency in Nginx configuration to automatically block abnormal IPs
- WAF integration
Rule base matching: Enable web application firewalls (e.g. CDN5 WAF, Cloudflare rule sets) to block SQL injection, XSS, and other exploits
Human-Machine Verification: Trigger CAPTCHA verification on suspicious requests to distinguish between real users and automated scripts
API security reinforcement: Adopt OAuth 2.0 authentication, request signature, and timestamp verification to prevent API interface abuse
5. How to choose an APP security provider?
1. Ensure a T-level protection level, as well as flexible broadband and real-time cleaning capabilities.Sudun CDN为企业打造集分布式 DDoS 防护、CC 防护、WAF 防护、BOT 行为分析为一体的安全加速解决方案。提供用户行为洞见，实现数据和运营决策联动，驱动云上业务稳定安全持续增长
2. Is the SDK integrated quickly? SDK development kit for Speed Shield CDN, simple integration, fast access, ignoring DDOS and CC attacks.
3. After-sales support: whether the service provider can respond immediately to solve the problem.