Was ist ein DDoS-Angriff?

 

What is a DDoS Attack? | A Radware Minute

Ideological and Social Causes: Hacktivists, activists, and individuals with strong convictions may launch DDoS attacks to disrupt operations, raise awareness, or silence opposing voices. This can target government agencies, corporations, or organizations perceived as violating ethical principles or societal norms.

Malicious Competition: In the realm of business, DDoS attacks can be used by competitors to disrupt a rival's online presence and gain an unfair advantage. By overwhelming a competitor's servers, they aim to hinder their ability to serve customers and potentially damage their reputation.

Financial Gain: DDoS attacks can be wielded as an extortion tool. Attackers may cripple an organization's online services and demand a ransom in exchange for restoring normalcy. This tactic often preys on businesses heavily reliant on online operations, forcing them into difficult choices.

Personal Grudges and Vendetta: DDoS attacks can be fueled by personal vendettas or disgruntled individuals seeking revenge against an organization or individual. This can manifest in attempts to disrupt online operations, damage reputation, or simply cause inconvenience.

Purely Destructive Acts: In some cases, DDoS attacks might be motivated by a desire for chaos or disruption. Perpetrators may find amusement in exploiting vulnerabilities and causing havoc, regardless of the specific target or desired outcome.

A Coordinated Deluge: Unlike traditional denial-of-service attacks originating from a single source, DDoS attacks unleash a coordinated and highly concentrated bombardment. Perpetrators wield a distributed network of compromised devices, known as a botnet. This “army” can encompass millions of unsuspecting personal computers, smartphones, and even Internet-of-Things (IoT) gadgets, unwittingly becoming tools in the malicious campaign.

Exploiting Vulnerabilities: Attackers employ various tactics to commandeer these devices, including malware deployment or exploiting unpatched software vulnerabilities. Once compromised, these devices become mere puppets under the attacker’s control, their resources and capabilities channeled towards a singular, malicious objective.

Democratization of Disruption: The accessibility of botnets has emerged as a concerning trend. Malicious actors can now rent out these botnets through “attack-for-hire” services. This effectively lowers the technical barrier to entry for potential attackers, widening the pool and amplifying the potential impact of DDoS attacks. This necessitates heightened vigilance and the implementation of robust security measures to combat this evolving threat landscape.

Involuntary Participants: It is crucial to recognize that the compromised devices within a botnet are involuntary participants. They are not actively involved in the attack but rather unwitting victims, manipulated by the attacker to orchestrate the digital assault.

Shifting Targets: While traditional DDoS attacks may have focused on individual servers, they now often target the underlying network infrastructure. Attackers strategically target crucial components like routers and switches, aiming to saturate the network's bandwidth capacity. This effectively disrupts connectivity and hinders access to the targeted resources, causing significant downtime and potential financial losses.

By delving into the intricate mechanics of DDoS attacks and recognizing their evolving nature, organizations and individuals can equip themselves with the necessary knowledge to mitigate risks and bolster their online resilience.

Technical Repercussions
At a technical level, DDoS attacks can cause severe disruptions to online services. They can lead to the unavailability of critical services, loss of productivity, and extensive remediation costs. The scale of these attacks has been rising tremendously with the advancement of the Internet of Things (IoT), making them a significant concern for cybersecurity.

DDoS attacks can create downtime, which can lead to revenue loss and erode consumer trust. They can also distract IT teams, giving hackers the chance to exploit other vulnerabilities, steal data, or infect a network with various forms of malware.

Economic Ramifications
The economic impact of DDoS attacks can be substantial. They can cost an organization millions of dollars in terms of remediation costs, lost revenue, lost productivity, loss of market share, and damage to brand reputation. Downtime can be extremely costly, depending on the type of business and the size of the organization.

Moreover, DDoS attacks can have indirect economic effects. For instance, they can lead to increased cybersecurity spending and higher insurance premiums. They can also result in regulatory fines if the attacks lead to data breaches or non-compliance with data protection regulations.

Attack on LCK Spring 2024 (February 2024): Recent matches in the LCK Spring 2024 season faced disruptions caused by persistent ping issues attributed to DDoS attacks. These disruptions led to prolonged technical pauses, impacting players and fans, both online and on-site.

Attack on Overwatch 2 (February 2024): The popular online multiplayer game Overwatch 2 was hit with a major DDoS attack. The attack caused major issues for players, disrupting gameplay and causing widespread frustration.

Attack on AWS (February 2020): Amazon Web Services (AWS) reported mitigating a massive DDoS attack that saw incoming traffic at a rate of 2.3 terabits per second (Tbps). The attackers responsible used hijacked Connection-less Lightweight Directory Access Protocol (CLDAP) web servers. AWS did not disclose which customer was targeted by the attack.

Attack on GitHub (February 2018): This attack reached 1.3 Tbps, sending packets at a rate of 126.9 million per second. The GitHub attack was a memcached DDoS attack, so there were no botnets involved. Instead, the attackers leveraged the amplification effect of a popular database caching system known as memcached. By flooding memcached servers with spoofed requests, the attackers were able to amplify their attack by a magnitude of about 50,000 times.

Attack on Google (September 2017): This attack is considered the largest DDoS attack to date, reaching a size of 2.54 Tbps. The attackers sent spoofed packets to 180,000 web servers, which in turn sent responses to Google. This was not an isolated incident as the attackers had directed multiple DDoS attacks at Google’s infrastructure over the previous six months.

Attack on Dyn (October 2016): This massive DDoS attack was directed at Dyn, a major DNS provider. The attack created disruption for many major sites, including Airbnb, Netflix, PayPal, Visa, Amazon, The New York Times, Reddit, and GitHub. This was done using malware called Mirai, which creates a botnet out of compromised Internet of Things (IoT) devices such as cameras, smart TVs, radios, printers, and even baby monitors.

Attack on Occupy Central, Hong Kong (2014): This attack targeted the Occupy Central movement in Hong Kong. The movement’s websites were hit with a massive DDoS attack, disrupting their online presence and communication.

Loss of Revenue: A DDoS attack can disrupt an organization’s online services, preventing potential customers from completing transactions and leading to significant revenue losses. This is particularly damaging for e-commerce platforms and businesses heavily reliant on online services.

Mitigation Expenses: Implementing robust DDoS mitigation measures is essential for effectively thwarting attacks. Organizations may opt for hardware-based solutions, cloud-based protection, or hybrid approaches, each with varying costs dependent on the attack’s scale and complexity.

Potential Ransom Payments: Some DDoS attacks are accompanied by ransom demands, adding to the financial burden on the targeted organization.

Financial Implications

Revenue Loss: DDoS attacks can disrupt online banking, stock trading, and payment processing systems. The resulting downtime can lead to significant revenue losses.

Reputation Damage: Customers expect seamless online services from financial institutions. Any disruption can harm the institution's reputation and erode customer trust.

Regulatory Compliance: Financial organizations must comply with strict regulations regarding data security and availability. DDoS attacks can jeopardize compliance.

Technological Impact

Network Congestion: DDoS floods overwhelm network infrastructure, causing congestion and latency. This affects real-time transactions and communication.

Resource Exhaustion: Attackers target servers, firewalls, and load balancers, exhausting their resources and rendering them ineffective.

Mitigation Costs: Financial firms invest heavily in DDoS mitigation solutions to protect their systems.

Critical Services: Healthcare relies on digital systems for patient records, telemedicine, and medical equipment. DDoS attacks disrupt these services.

Public Health Impact: DDoS attacks on healthcare institutions can hinder pandemic response efforts, vaccination campaigns, and health information dissemination.

Supply Chain Disruption: Pharmaceutical companies, medical device manufacturers, and logistics providers face supply chain disruptions during attacks.

Patient Safety: Delayed access to medical records or emergency services due to DDoS attacks can endanger patient lives.

Access to Resources: Libraries, research databases, and e-learning portals become inaccessible during attacks.

Online Learning Platforms: Educational institutions increasingly rely on online learning platforms. DDoS attacks disrupt classes, exams, and student collaboration.

Administrative Systems: DDoS attacks affect administrative functions such as student enrollment, payroll, and communication.

Student Experience: Downtime impacts student experience, especially during critical periods like exams or admissions.

Government: Attacks on government websites can disrupt citizen services, tax filing, and public information dissemination.

E-Commerce: Retailers face revenue loss during peak shopping seasons due to DDoS attacks.

Gaming: Online gaming platforms experience latency, affecting user experience and in-game transactions.

Media and Entertainment: Streaming services, news websites, and social media platforms are vulnerable to DDoS attacks.

Impacts on Freedom of Expression: DDoS attacks can be used to target media outlets or political websites, potentially stifling freedom of expression and leading to censorship.

Potential for Escalation into Geopolitical Tensions: DDoS attacks can be used as tools in larger geopolitical conflicts, potentially escalating tensions between nations.

Erosion of Trust in Digital Services: DDoS attacks cast a shadow of doubt on an organization’s ability to safeguard customer data and ensure reliable services. The erosion of trust among customers can cause long-term reputational damage, impacting brand loyalty and new customer acquisition.

Direct Costs: These are costs associated with downtime/latency, loss of immediate revenue, and personnel costs associated with mitigating attacks. For instance, when a DDoS attack disrupts an organization’s online services, potential customers cannot complete transactions, leading to significant revenue losses. Implementing robust DDoS mitigation measures is essential to thwarting attacks effectively. Organizations may opt for hardware-based solutions, cloud-based protection, or hybrid approaches, each with varying costs dependent on the attack’s scale and complexity.

Indirect Costs: These would be customer churn, regulatory repercussions, and compromised data. For example, DDoS attacks cast a shadow of doubt on an organization’s ability to safeguard customer data and ensure reliable services. The erosion of trust among customers can cause long-term reputational damage, impacting brand loyalty and new customer acquisition.

• Ungewöhnlich langsame Netzwerkleistung
• Nichtverfügbarkeit eines bestimmten Netzdienstes und/oder einer Website
• Die Unfähigkeit, auf eine Website zuzugreifen
• Eine IP-Adresse stellt in einer begrenzten Zeitspanne ungewöhnlich viele Anfragen

• Server responds with a 503-error due to a service outage
• Die Log-Analyse zeigt eine starke Zunahme des Netzwerkverkehrs
• Abweichende Verkehrsmuster wie hohe Auslastung zu ungewöhnlichen Tageszeiten oder abweichend erscheinende Muster

HTTP Floods: Attackers flood web servers with a massive number of HTTP requests. These requests overload the server’s processing capacity, leading to service disruption.

HTTPS Attacks: Similar to HTTP floods, but with encrypted traffic. Attackers exploit SSL/TLS handshakes, consuming server resources during connection setup.

SMTP and Email Attacks: By bombarding email servers with excessive requests, attackers disrupt email communication and overload mail servers.

VOIP Attacks: Targeting Voice over IP (VOIP) services, these attacks flood SIP (Session Initiation Protocol) servers, causing call drops and service degradation.

FTP Attacks: Attackers overwhelm File Transfer Protocol (FTP) servers, hindering file transfers and access.

“Low and Slow” Attacks: These are more subtle. Attackers send requests at a slow pace, avoiding detection thresholds. For example:

Slowloris: Opens multiple connections to a web server and sends partial HTTP requests, keeping connections open indefinitely.

R-U-Dead-Yet (RUDY): Sends slow POST requests to exhaust server resources.

Flood Attacks: High-volume requests flood the application, saturating its resources. These can be HTTP floods, HTTPS floods, or other protocol-specific floods.

Resource Exhaustion: Application Layer DDoS attacks drain server memory, CPU, and bandwidth. This affects response times and overall performance.

Mitigation Complexity: Unlike network-based attacks, application layer attacks require specialized defenses that inspect application-level traffic.

Complex Attribution: Identifying the true source of these attacks is challenging due to spoofed IP addresses and botnets.

Service Disruption: Critical services like web applications, email, and VOIP become unusable during attacks.

Figure 3: How a Layer-7 Application DDoS Attack

What is a Layer 7 DDoS Attack? | A Radware Minute

High Traffic Volume: These attacks generate an enormous amount of traffic, saturating the bandwidth of the targeted network.

IP Spoofing: Attackers often use IP spoofing to mask the source of the attack traffic, making it difficult to block and trace back.

Use of Botnets: Attackers often leverage botnets - networks of compromised devices - to generate the massive traffic volume required for these attacks.

Protocol Exploitation: Common network protocols such as NTP, DNS, and SSDP are exploited to amplify the attack traffic.

Bandwidth Saturation: Volumetric DDoS attacks consume all available network bandwidth, affecting network speed and overall performance.

Service Disruption: Essential services such as web servers, databases, and cloud services become inaccessible during attacks.

Mitigation Complexity: Unlike traditional network-based attacks, volumetric DDoS attacks require specialized defenses that can handle high volumes of traffic and distinguish between legitimate and malicious requests.

Complex Attribution: Pinpointing the actual source of these attacks is challenging due to tactics like IP spoofing and the use of botnets.

High Request Volume: Web DDoS Tsunami attacks generate an exceptionally high number of requests per second (RPS), overwhelming targeted servers and infrastructure.

Encryption: Attack traffic is often encrypted, making it difficult to discern malicious requests from legitimate ones.

Application-Level Attack Methods: These include HTTPS Get, Push, and Post request attacks with dynamic parameters behind proxies. Each request appears innocuous, making timely detection challenging.

Continuous Morphing: Web DDoS Tsunami attacks continuously evolve, altering their patterns and characteristics. This dynamic behavior prolongs the attack duration and exacerbates downtime.

Sophisticated Evasion Techniques:

Randomized Headers: Attackers manipulate HTTP methods, headers, and cookies, making their requests appear legitimate.

IP Spoofing: They spoof IP addresses, complicating attribution and filtering.

Impersonation of Third-Party Services: Attackers mimic popular embedded third-party services, further camouflaging their intent.

Resource Exhaustion: These attacks drain server memory, CPU, and bandwidth, affecting response times and overall performance.

Service Disruption: Critical services like web applications, email, and VOIP become unusable during attacks.

Mitigation Complexity: Unlike network-based attacks, application layer attacks require specialized defenses that inspect application-level traffic.

Complex Attribution: Identifying the true source of these attacks is challenging due to spoofed IP addresses and botnets.

Scrubbing-Kapazität und globales Netzwerk
DDoS attacks are increasing in quantity, severity, complexity, and persistence. Bei umfangreichen oder gleichzeitigen Angriffen sollten Cloud-DDoS-Dienste ein robustes, globales Sicherheitsnetzwerk bereitstellen, das mit einer Mitigationskapazität von mehreren Tbps skalierbar ist und über spezielle Scrubbing-Zentren verfügt, die sauberen Datenverkehr vom Datenverkehr der DDoS-Angriffe trennen.

Verhaltensbasierter Schutz
Eine DDoS-Abwehrlösung, die Angriffe ohne Beeinträchtigung des legitimen Datenverkehrs blockiert, ist dabei der Schlüssel. Lösungen, die Machine Learning und verhaltensbasierte Algorithmen nutzen, um legitimes Verhalten zu verstehen und bösartige Angriffe automatisch zu blockieren, sind unabdingbar. Dies erhöht die Schutzgenauigkeit und minimiert Fehlalarme.

Mehrere Bereitstellungsoptionen
Die Flexibilität der Bereitstellungsmodelle ist von entscheidender Bedeutung, damit eine Organisation ihren DDoS-Abwehrdienst an ihre Bedürfnisse, ihr Budget, ihre Netzwerktopologie und ihr Bedrohungsprofil anpassen kann. The appropriate deployment model-hybrid, on-demand or always-on cloud protection-will vary based on network topology, application hosting environments and sensitivity to delays and latency.

Automatisierung
Angesichts der heutigen dynamischen und automatisierten DDoS-Angriffe wollen sich Organisationen nicht auf einen manuellen Schutz verlassen. A service that does not require any customer intervention with a fully automated attack lifecycle-data collection, attack detection, traffic diversion and attack mitigation-ensures better quality protection.

• What is occuring
• Wann der Angriff anfing
• Welche Schritte unternommen werden, um den Angriff zu mildern

• Auswirkungen auf Nutzer und Kunden
• Welche Ressourcen (Anwendungen, Dienste, Server usw.) betroffen sind

• Welche Art von DDoS-Angriff ist es? Ist es eine Flood auf Netzwerkebene oder ein Angriff auf Applikationsebene?
• Was sind die Angriffsmerkmale? Wie groß ist der Angriff, sowohl in Bits pro Sekunde als auch in Paketen pro Sekunde?
• Wie sieht das Angriffsmuster aus? Ist es eine einzige anhaltende Flood oder ein Burst-Angriff? Does it involve a single protocol, or does it involve multiple attack vectors?

• Kommt der Angriff von einer einzigen IP-Quelle oder von mehreren Quellen? Können Sie sie identifizieren?
• Bleiben die Angriffsziele dieselben oder ändern die Angreifer ihre Ziele im Laufe der Zeit?

Criminal Charges: DDoS attacks are illegal, and the attacker may face criminal charges. For instance, under the Computer Misuse Act 1990 in the UK, individuals involved in DDoS attacks face up to 10 years in prison. In the United States, individuals participating in DDoS attacks risk being charged with legal offenses at the federal level, both criminally and civilly.

Liability: If a DDoS attack causes harm to an individual or a business, the attacker can be held liable for the damages.

Violation of Terms of Service: DDoS attacks violate the terms of service of most internet service providers and websites.

Potential for Abuse: Despite these arguments, DDoS attacks have the potential to be abused and can cause significant harm. They can disrupt services, cause financial loss, and infringe on people’s rights to access information. Therefore, even if they are used with good intentions, DDoS attacks can have negative consequences.

Civil Disobedience: Some proponents of DDoS attacks argue that they can be seen as a form of civil disobedience or online protest. In this view, DDoS attacks are akin to sit-ins or other forms of peaceful protest, used to draw attention to an issue or cause.

Ethical Hacking: Ethical hacking, also known as “white hat” hacking, involves using hacking skills to identify and fix vulnerabilities in systems. Ethical hackers can play a crucial role in preventing DDoS attacks by identifying potential weaknesses that could be exploited and helping organizations strengthen their defenses.

IoT Botnets: The vast and often poorly secured landscape of Internet-of-Things (IoT) devices presents a fertile ground for building powerful botnets capable of launching devastating attacks.

Application-Layer Attacks: These attacks target specific vulnerabilities in applications, bypassing traditional network-based defenses and potentially causing significant damage.

Multi-Vector Attacks: Combining multiple attack techniques, such as volumetric and application-layer attacks, overwhelms defenses and makes them more difficult to mitigate.

Data Breaches: By overwhelming a network with traffic, attackers can distract security personnel and create an opening to steal sensitive data.

Ransomware Attacks: DDoS attacks can be used to disrupt operations and pressure organizations into paying ransom demands.

Scalability: They can seamlessly handle large-scale attacks by leveraging the vast resources of the cloud provider, eliminating the need for significant on-premises infrastructure investment.

Global Reach: With geographically distributed points of presence, cloud-based solutions can effectively mitigate attacks originating from diverse locations.

Flexibility: Cloud-based solutions offer a subscription-based model, allowing organizations to scale their defenses up or down as needed, optimizing costs and resource allocation.

Targeted Attacks on Critical Infrastructure: Critical infrastructure, such as power grids, financial institutions, and healthcare providers, may become more susceptible to targeted DDoS attacks aimed at causing widespread disruption and potentially jeopardizing public safety. The potential impact of such attacks necessitates robust defenses and coordinated response strategies among government agencies, critical infrastructure operators, and cybersecurity professionals.

Emergence of “Mega-Attacks”: The growing number of connected devices, the widespread adoption of IPv6, and the increasing availability of powerful botnets could facilitate the launch of larger and more complex attacks with the potential to cripple critical infrastructure and online services.

AI-powered Attacks: Attackers may leverage artificial intelligence (AI) to automate and personalize attacks, making them more challenging to detect and mitigate. AI could be used to:

• Identify and exploit vulnerabilities in an organization’s defenses.
• Launch coordinated attacks that adapt to ongoing mitigation efforts.
• Generate highly targeted phishing and social engineering attacks that are more likely to trick users.

Increased Geopolitical Implications: In a world rife with geopolitical tensions, DDoS attacks may be used as tools of cyberwarfare, aimed at disrupting rival nations’ infrastructure, or influencing public opinion. Proactive measures and international collaboration will be crucial to mitigate the impact of such attacks.