Contents

CEH-Module10 - Denial of Service

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DoS - Denial Of Service

A Denial-of-Service (DoS) attack is a malicious attempt to disrupt the normal functioning of a network, service, or website by overwhelming it with a flood of illegitimate traffic or requests. The goal of a DoS attack is to make a system or network unavailable to its intended users, causing a denial of service.

There are various types of DoS attacks, and they can target different layers of a network stack. Some common types of DoS attacks include:

  1. Flooding Attacks:

    • Ping Flood: Inundates the target with ICMP Echo Request (ping) packets.
    • SYN/ACK Flood: Overwhelms the target with a flood of TCP connection requests.
  2. Application Layer Attacks:

    • HTTP Flood: Overloads a web server with a massive number of HTTP requests.
    • DNS Amplification: Exploits open DNS servers to generate a flood of responses to a victim’s IP address.
  3. Protocol Exploitation:

    • Smurf Attack: Abuses the Internet Control Message Protocol (ICMP) to amplify the attack.
    • DNS Spoofing: Manipulates the Domain Name System to redirect legitimate traffic.
  4. Resource Depletion Attacks:

    • Slowloris: Exploits the way web servers handle concurrent connections by keeping them open as long as possible.
    • Resource Exhaustion: Consumes system resources, such as CPU, memory, or bandwidth, to render the system unusable.
  5. Distributed Denial-of-Service (DDoS) Attacks:

    • In a DDoS attack, multiple compromised computers (often a botnet) are used to launch a coordinated attack on a target, making it more difficult to mitigate.

The motive behind DoS attacks can vary. It could be for ideological reasons, revenge, competition, or just for the thrill of causing disruption. Organizations deploy various security measures, such as firewalls, intrusion detection/prevention systems, and content delivery networks, to mitigate the impact of DoS attacks.

Using msfconsole and hping3, we can flood a remote machine as shown below:

MSFconsole auxiliary/dos/tcp/synflood

  • msf > use auxiliary/dos/tcp/synflood
  • set RHOST 192.168.1.100
  • set SHOST 192.168.1.10
  • set RPORT 80
  • run

hping3

  • hping3 -S (Target IP Address) -a (Spoofable IP Address) -p 22 –flood and press Enter.

-S: sets the SYN flag; -a: spoofs the IP address; -p: specifies the destination port; and –flood: sends a huge number of packets

PoD attack

In a PoD attack, the attacker tries to crash, freeze, or destabilize the targeted system or service by sending malformed or oversized packets using a simple ping command.

For example, the attacker sends a packet that has a size of 65,538 bytes to the target web server. This packet size exceeds the size limit prescribed by RFC 791 IP, which is 65,535 bytes. The receiving system’s reassembly process might cause the system to crash.

hping3 -d 65538 -S -p 21 --flood 10.10.1.11

DoS Attack using Raven-Storm

run raven-storm utility by initating the command, sudo rst in parrot machine. This will start raven-storm utility.

Next run below commands and run it.

l4

ip TargetIP ip 192.168.44.1

port 80

threads 20000

run

Perform a DDoS Attack using HOIC

HOIC (High Orbit Ion Cannon) is a network stress and DoS/DDoS attack application. This tool is written in the BASIC language. It is designed to attack up to 256 target URLs simultaneously. It sends HTTP, POST, and GET requests to a computer that uses lulz inspired GUIs. It offers a high-speed multi-threaded HTTP Flood; a built-in scripting system allows the deployment of “boosters,” which are scripts designed to thwart DDoS countermeasures and increase DoS output.

HOIC is a windows GUI tool to perform DDOS attack.

Perform a DDoS Attack using LOIC

LOIC (Low Orbit Ion Cannon) is a network stress testing and DoS attack application. We can also call it an application-based DOS attack as it mostly targets web applications. We can use LOIC on a target site to flood the server with TCP packets, UDP packets, or HTTP requests with the intention of disrupting the service of a particular host.

DDoS - Distributed Denial Of Service

A Distributed Denial-of-Service (DDoS) attack is an advanced and more potent form of a Denial-of-Service (DoS) attack. In a DDoS attack, multiple compromised computers or devices are used to flood a target system or network with an overwhelming volume of traffic, making it difficult for the targeted service to function properly and causing a denial of service to legitimate users.

The key characteristic of a DDoS attack is the use of a distributed network of computers, often referred to as a botnet, to launch the attack. A botnet is a collection of compromised devices, such as computers, servers, or Internet of Things (IoT) devices, that are under the control of a malicious actor (the attacker). The attacker orchestrates the attack by instructing the botnet to send a massive amount of traffic or requests to the target simultaneously.

DDoS attacks can be categorized into several types based on the nature of the attack:

  1. Volumetric Attacks: Overwhelm the target with a high volume of traffic, consuming its bandwidth and resources. Examples include UDP amplification attacks and DNS amplification attacks.

  2. Protocol Attacks: Exploit vulnerabilities in network protocols, such as the TCP/IP stack, to deplete server resources. For example, SYN/ACK floods overwhelm a target by sending a flood of TCP connection requests.

  3. Application Layer Attacks: Target specific applications or services, such as web servers or databases, by sending a large number of legitimate-looking requests. Examples include HTTP floods and Slowloris attacks.

  4. Reflective/Amplification Attacks: Exploit servers that respond with a larger payload than the original request, amplifying the impact of the attack. DNS amplification and NTP amplification are common examples.

  5. Botnets: The use of a large number of compromised devices, often belonging to unsuspecting users, to generate and send a massive volume of traffic to the target.

  6. Variety of Attack Vectors: DDoS attacks can employ various methods and attack vectors, including volumetric attacks, protocol attacks, and application layer attacks, to overwhelm the targeted system.

  7. Amplification: Some DDoS attacks leverage reflection or amplification techniques, exploiting vulnerabilities in certain services to amplify the impact of the attack.

  8. Distributed Nature: The traffic comes from multiple sources, making it harder to block or filter out malicious requests. This distributed approach enhances the effectiveness and resilience of the attack.

DDoS attacks are often used to disrupt online services, websites, or networks. Motives behind DDoS attacks can range from ideological reasons, revenge, or extortion to gaining a competitive advantage in the online space. Mitigating DDoS attacks involves implementing robust security measures, using content delivery networks (CDNs), and deploying specialized DDoS protection services that can detect and filter out malicious traffic.

Detect and Protect Against DDoS Attacks using Anti DDoS Guardian

Anti DDoS Guardian is a DDoS attack protection tool. It protects IIS servers, Apache serves, game servers, Camfrog servers, mail servers, FTP servers, VOIP PBX, and SIP servers and other systems. Anti DDoS Guardian monitors each incoming and outgoing packet in Real-Time. It displays the local address, remote address, and other information of each network flow. Anti DDoS Guardian limits network flow number, client bandwidth, client concurrent TCP connection number, and TCP connection rate. It also limits the UDP bandwidth, UDP connection rate, and UDP packet rate.

Botnets

A botnet is a network of compromised computers or devices that are under the control of a malicious actor, known as the “botmaster” or “controller.” These compromised devices, often referred to as “bots” or “zombies,” are typically infected with malware that allows the attacker to remotely control them. The botmaster can use the botnet to perform various malicious activities, and one common use is to launch coordinated attacks, such as Distributed Denial-of-Service (DDoS) attacks.

Here are key characteristics and features of botnets:

  1. Compromised Devices: The devices that make up a botnet can include personal computers, servers, routers, and even Internet of Things (IoT) devices. These devices are compromised through the installation of malicious software without the knowledge or consent of their owners.

  2. Remote Control: Once a device is infected and becomes part of a botnet, it can be remotely controlled by the botmaster. The botmaster issues commands to the bots, directing them to perform specific actions.

  3. Command and Control (C&C) Servers: Botnets typically have one or more command and control servers that act as the communication hub between the botmaster and the compromised devices. The C&C servers send instructions to the bots and collect information from them.

  4. Distributed Nature: Botnets are distributed across multiple locations, making it challenging to trace and take down the entire network. This distributed nature enhances the resilience and effectiveness of the botnet.

  5. Malicious Activities: Botnets can be used for various malicious purposes, including:

    • Launching DDoS attacks to overwhelm and disrupt targeted websites or services.
    • Sending spam emails or phishing messages on a massive scale.
    • Stealing sensitive information, such as login credentials or financial data.
    • Performing click fraud, where bots click on online ads to generate revenue fraudulently.
    • Distributing additional malware or participating in coordinated cyberattacks.

Detecting and mitigating botnets is a challenging task for cybersecurity professionals. Anti-malware software, intrusion detection/prevention systems, and network security measures are employed to identify and remove bot infections. Additionally, collaboration among cybersecurity organizations and internet service providers is crucial to track and dismantle botnets effectively.

DDoS Propagation Methods

General concepts behind central source, back chaining, and autonomous propagation in DDoS attacks:

1. Central Source Propagation:

  • Mechanism: Attack code resides on a central server. Compromised bots download and execute the code from this server, becoming new attack agents.
  • Example: Mirai botnet, which infected IoT devices and launched large-scale attacks by downloading attack code from a central server.
  • Advantages for attackers: Easy to manage, maintain code centrally, scale the attack quickly.
  • Disadvantages for attackers: Single point of failure (central server), easier to track and mitigate.

2. Back Chaining Propagation:

  • Mechanism: Compromised bots act as both attack agents and infection vectors. They scan for vulnerabilities and infect new systems, which then join the attack and scan for more victims.
  • Example: Slammer worm, which propagated rapidly through networks by infecting vulnerable machines and using them to scan for further targets.
  • Advantages for attackers: Decentralized, difficult to track, highly resilient.
  • Disadvantages for attackers: Slower propagation, depends on vulnerability presence, complex to manage.

3. Autonomous Propagation:

  • Mechanism: Attack code embedded within the initial payload infects new systems without needing to download additional code. The infected system automatically scans and exploits new targets.
  • Example: Nimda worm, which spread through email attachments and network shares, carrying its own attack code for further propagation.
  • Advantages for attackers: Fast, efficient, highly evasive.
  • Disadvantages for attackers: Complex to develop, requires specific vulnerabilities, may be resource-intensive for infected systems.

Basic Categories of DoS/DDoS Attacks

Distributed Denial of Service (DDoS) and Denial of Service (DoS) attacks come in various forms, each utilizing different methods to overwhelm or disrupt a target’s resources. Here are some basic categories of DDoS/DoS attack vectors:

  1. Volume-Based Attacks:

    • Consume bandwidth of the target network or service.
    • UDP Flood: Overwhelms the target with a high volume of UDP (User Datagram Protocol) packets.
    • ICMP Flood: Floods the target with ICMP (Internet Control Message Protocol) echo request (ping) packets.
    • TCP SYN/ACK Flood: Exploits the TCP three-way handshake by sending a large number of SYN or ACK packets to overwhelm the target’s resources.
    • Measured in bits per second.
  2. Protocol-Based Attacks:

    • Consume other types of resources like connection state tables present in network infrastructure components like load balancers, firewalls and application servers.
    • Ping of Death: Sends oversized ICMP packets to crash the target’s system or network.
    • Smurf Attack: Abuses the ICMP protocol to flood a target with traffic, often by using a large number of compromised intermediary systems (amplifiers).
    • Measured in packets per second.
  3. Application Layer Attacks:

    • Consume resources or services of an application thereby making the application not available to legitimate users.
    • HTTP/HTTPS Flood: Overwhelms web servers by sending a massive number of legitimate-looking HTTP/HTTPS requests.
    • Slowloris: Exploits the way web servers handle connections by keeping numerous connections open but sending requests very slowly.
    • DNS Amplification: Abuses DNS servers by sending a small number of requests with a spoofed source address, triggering large responses to the victim.
    • Measured in requests per second.
  4. Resource Depletion Attacks:

    • Brute Force Attacks: Overloads authentication mechanisms by attempting to exhaust resources through a large number of login attempts.
    • SYN/ACK Reflection: Exploits the connection establishment process by using reflective amplification.
  5. Application Exploitation Attacks:

    • Zero-Day Exploits: Targets vulnerabilities in software or applications that are not yet known or patched by the vendor.
    • Buffer Overflow: Exploits vulnerabilities in software by overrunning the buffer’s capacity, leading to unintended behavior.
  6. DNS Spoofing or Cache Poisoning:

    • Manipulates DNS responses to redirect legitimate traffic to malicious destinations or overwhelm DNS servers.
  7. IoT-Based Attacks:

    • Exploits insecure Internet of Things (IoT) devices to create large botnets for launching DDoS attacks.
  8. Amplification Attacks:

    • NTP Amplification: Utilizes insecure NTP servers to amplify and reflect attack traffic.
    • DNS Amplification: Uses open DNS resolvers to amplify and reflect traffic towards the target.

Understanding these attack vectors is crucial for implementing effective mitigation strategies to protect against DDoS and DoS attacks.

UDP Flood Attack

A UDP flood attack is a type of Distributed Denial of Service (DDoS) attack that targets the User Datagram Protocol (UDP). In a UDP flood attack, the attacker overwhelms a target system with a large volume of UDP packets, causing it to become unreachable or slow in responding to legitimate requests.

UDP is a connectionless protocol that does not establish a direct connection before sending data, unlike the Transmission Control Protocol (TCP). This lack of connection establishment in UDP makes it easier for attackers to forge the source IP address of the packets, making it challenging to trace the origin of the attack.

Here’s how a UDP flood attack typically works:

  1. Volume of UDP Packets: The attacker generates a massive number of UDP packets and sends them to the target system.

  2. Forged Source IP Addresses: The attacker often spoofs or forges the source IP addresses in the UDP packets to make it difficult for the target to identify the actual source of the attack.

  3. Overwhelming the System: The target system receives an overwhelming number of UDP packets, and since UDP is connectionless, it does not have to establish a connection before processing the packets. This makes it easier for the attacker to flood the target system with a large volume of traffic.

  4. Resource Exhaustion: The continuous influx of UDP packets consumes the target’s network bandwidth and other resources, such as processing power and memory, leading to a slowdown or unavailability of services.

  5. Denial of Service: As a result, the targeted service becomes unavailable or experiences significant degradation in performance, leading to a denial of service for legitimate users.

UDP flood attacks are challenging to mitigate because the attacker can easily generate a large number of packets with minimal resources. Additionally, the lack of connection state in UDP makes it difficult to filter out malicious traffic from legitimate traffic based on established connections.

ICMP Flood Attack

An ICMP flood attack is a type of Distributed Denial of Service (DDoS) attack where an attacker overwhelms a target system with a massive volume of ICMP echo request packets (ping requests). This flood of requests consumes the target’s network bandwidth and resources, leading to a slowdown or unavailability of services for legitimate users. The attacker may also use techniques such as spoofing to make it challenging to trace the origin of the attack. Mitigation strategies include rate limiting, traffic filtering, and intrusion prevention systems.

Ping Of Death Attack

The “Ping of Death” is a type of Denial of Service (DoS) attack that exploits a vulnerability in the Internet Control Message Protocol (ICMP), specifically in the way some systems handle oversized or malformed ICMP packets. ICMP is used for various network-related tasks, including the widely known “ping” command that tests network connectivity.

In a Ping of Death attack, the attacker sends oversized or malformed ICMP packets to a target system with the intention of causing a buffer overflow. A buffer overflow occurs when data exceeds the space allocated for it in a program’s memory, potentially leading to the execution of malicious code or a crash of the system.

I’d be glad to explain Ping of Death (PoD) DDoS attacks in cybersecurity, but I’m unable to provide specific instructions or code that could be used for malicious purposes. My purpose is to be informative and helpful, and that includes protecting against harmful activities.

Understanding Ping of Death DDoS Attacks:

  • Concept: A PoD attack is a type of Denial-of-Service (DoS) attack that exploits vulnerabilities in how Internet Protocol (IP) packets are fragmented and reassembled. By sending malformed or oversized ICMP (ping) packets, attackers aim to crash, freeze, or reboot targeted systems, disrupting their availability.

  • Technical Details:

    • ICMP packets have a size limit of 65,535 bytes.
    • Attackers fragment oversized packets (EX: 65538 packets using ping command) into smaller pieces that exceed the limit when reassembled.
    • Vulnerable systems might not handle this overflow correctly, leading to crashes or instability.
    • ping IPAddress -l 655538 -t sends a ping packet with 65538 size continously until stopped.
  • Impact:

    • Disrupted services for users
    • Potential data loss or corruption
    • Reputational damage

Example:

Imagine a malicious actor targeting a website with a PoD attack. They craft oversized ICMP packets and fragment them before sending them to the website’s server. If the server lacks proper security measures, it might try to reassemble these fragments into a packet exceeding the size limit, causing the server to crash and the website to become unavailable.

Smurf Attack

A Smurf attack is a type of Distributed Denial of Service (DDoS) attack that takes advantage of the Internet Control Message Protocol (ICMP) and the way it handles broadcast traffic. This attack can cause a significant disruption in a target network by flooding it with a large volume of ICMP echo request (ping) packets.

Here’s how a Smurf attack typically works:

  1. Amplification Technique:

    • The attacker sends a large number of ICMP echo request packets (ping packets) to an IP broadcast address.
    • The source IP address in the packets is spoofed to appear as if it originates from the target system.
  2. Broadcast Address:

    • The broadcast address ensures that the ping packets are sent to all hosts within the specified network segment.
  3. Amplified Responses:

    • Each host on the network segment that receives the ping packet replies to the spoofed source address (which is the target system).
    • As a result, the target system is flooded with a massive volume of ICMP echo reply packets.
  4. Network Overload:

    • The sheer volume of responses overwhelms the target system’s resources, such as bandwidth, processing power, and memory.
    • Legitimate traffic to the target is disrupted, leading to a denial of service.

The term “Smurf” comes from the original exploit tool called “Smurf” that was created to automate this type of attack.

To prevent Smurf attacks and mitigate their impact, network administrators can implement several measures:

  • Disable IP Directed Broadcasts: By disabling the forwarding of broadcast packets to all hosts, a network can avoid becoming a target for Smurf attacks.

  • Ingress Filtering: Internet Service Providers (ISPs) can implement ingress filtering to drop packets with spoofed source addresses at their network borders, preventing them from reaching the target.

  • Rate Limiting: Implement rate limiting on ICMP traffic to mitigate the impact of an ICMP flood.

It’s worth noting that as network security has evolved, and awareness of these types of attacks has increased, Smurf attacks have become less common. However, it’s essential for organizations to remain vigilant and employ a variety of security measures to protect against different types of DDoS attacks.

Pulse Wave Attack

A pulse wave attack, also known as a pulsating attack, is a sophisticated and potent type of Denial-of-Service (DoS) attack that leverages rapid bursts of malicious traffic to overwhelm and disable targeted systems. Here’s a breakdown:

What it is:

  • Method: Instead of a sustained flood of traffic, pulse wave attacks send short, intense bursts of attack packets in quick succession, resembling a sawtooth pattern.
  • Effectiveness: This approach bypasses some traditional DDoS mitigation techniques designed for continuous attacks, making it highly disruptive and challenging to defend against.
  • Targets: Pulse wave attacks can target various systems, including websites, servers, networks, and infrastructure.

How it works:

  1. Attack preparation: Attackers typically use a large network of compromised devices (botnet) to launch the attack.
  2. Bursting traffic: Attackers control the botnet to send coordinated bursts of malicious traffic at the target, often targeting specific vulnerabilities or overwhelming resources.
  3. Short bursts, high impact: Each burst can last for seconds or minutes, but is powerful enough to cause temporary outages or disruptions.
  4. Rapid repetition: The bursts are repeated with short intervals, creating a continuous pulsating effect that keeps the target under pressure.

Impact:

  • Service disruptions: Pulse wave attacks can cause websites, applications, or entire networks to become unavailable or slow down significantly.
  • Resource exhaustion: The bursts can overload servers, routers, and other network equipment, leading to resource depletion and performance degradation.
  • Financial losses: Downtime and lost productivity can translate to significant financial losses for businesses and organizations.

Example:

Imagine a hospital website being targeted by a pulse wave attack. The attackers send intense bursts of traffic aimed at overloading the web server, causing temporary outages that prevent patients from booking appointments or accessing medical records. These brief but repeated disruptions can create significant chaos and hinder critical healthcare services.

Zero Day DDoS Attack

  • A zero-day DDoS attack refers to an attack that exploits vulnerabilities in software, networks, or protocols that are not yet known to the vendor or the public. In the context of DDoS attacks, this typically means leveraging previously unknown weaknesses in the targeted system or application.
  • Zero-day vulnerabilities are called “zero-day” because the targeted entity has zero days of awareness or preparation before the attack takes place. Attackers take advantage of these vulnerabilities before they are discovered and patched by the software or system developers.

Syn Flood Attack

A SYN flood attack is a type of Denial of Service (DoS) attack that exploits the three-way handshake process in the Transmission Control Protocol (TCP), a fundamental communication protocol used in computer networks.

Here’s how a normal three-way handshake works in TCP:

  1. SYN (Synchronize): The client sends a SYN packet to the server to initiate a connection.
  2. SYN-ACK (Synchronize-Acknowledge): The server responds with a SYN-ACK packet, acknowledging the request and indicating its willingness to establish a connection.
  3. ACK (Acknowledge): The client sends an ACK packet to confirm the establishment of the connection.

In a SYN flood attack, the attacker sends a large number of SYN packets to the target server but does not respond to the SYN-ACK packets from the server. The goal is to overwhelm the server’s resources, such as the available connection slots or the amount of memory allocated for maintaining half-open connections. As a result, legitimate connection requests from other users are unable to be processed, leading to a denial of service for those users.

Key characteristics of SYN flood attacks include:

  • High Volume of SYN Requests: The attacker floods the target server with a massive number of SYN requests, often using spoofed or forged IP addresses to make tracing the source more challenging.

  • Exhaustion of Resources: The server allocates resources to each incoming SYN request and expects a corresponding ACK. In a SYN flood attack, the attacker does not respond to the SYN-ACK, causing the server to hold resources for incomplete connections.

Listen Queue and Timeout Mechanisms:

When a machine (ServerB) receives syn from another machine (ServerA), the machine received the syn request will move this connection to a “listen queue” for 75 seconds.

  • Listen Queue: The listen queue is a buffer where incoming connection requests are held before they are accepted by the server. If the listen queue is full due to a SYN flood attack, legitimate connection requests may be dropped, contributing to service denial.
  • Timeout Mechanisms: In some systems, if a connection request remains unacknowledged for a certain period (often around 75 seconds), it may be removed from the listen queue. Attackers may attempt to exploit this timeout period to consume resources and disrupt normal server operations.
  • Adjusting Parameters: Network administrators can consider adjusting the parameters related to the listen queue and timeout mechanisms to optimize them for their specific environment. This may involve increasing the size of the listen queue or adjusting timeout values to better withstand and mitigate SYN flood attacks.

To mitigate SYN flood attacks, network administrators can implement various countermeasures, including:

  1. SYN Cookies: This technique involves encoding information in the initial SYN-ACK response to track connection requests without allocating resources until the three-way handshake is complete.

  2. Rate Limiting: Implementing rate limits on the number of incoming connection requests from a single IP address can help prevent overwhelming the server.

  3. Firewalls and Intrusion Prevention Systems (IPS): Configuring these security measures to detect and block suspicious SYN flood patterns can provide an additional layer of defense.

  4. Load Balancers: Distributing incoming traffic across multiple servers using load balancers can help distribute the impact of a SYN flood attack.

  5. Monitoring and Anomaly Detection: Regularly monitoring network traffic and employing anomaly detection systems can help identify unusual patterns indicative of a SYN flood attack.

Fragmentation Attack

A fragmentation attack is a type of network attack that involves manipulating the size or content of data packets in a way that disrupts the normal functioning of networked systems or devices. This type of attack exploits the fragmentation process used in network protocols, particularly in the Internet Protocol (IP) suite.

Here’s how IP fragmentation normally works:

  1. When data is transmitted over a network, it is divided into smaller units called packets.

  2. Each packet contains a fragment of the original data along with header information that includes details like source and destination addresses, protocol type, and more.

  3. These packets are transmitted independently over the network and are reassembled at the destination.

In a fragmentation attack, the attacker manipulates the packet fragmentation process to create packets that may be improperly reassembled or cause disruptions in the targeted system. There are different types of fragmentation attacks, including:

  1. Overlapping Fragments: The attacker intentionally sends overlapping fragments, causing ambiguity in the reassembly process. This may lead to errors in the reconstructed data.

  2. Teardrop Attack: In a teardrop attack, the attacker sends fragmented packets with overlapping, oversized, or malformed payloads. When the target system attempts to reassemble these packets, it can lead to buffer overflow or system crashes.

  3. Ping of Death: This attack involves sending oversized ICMP (Internet Control Message Protocol) packets, exploiting the maximum packet size limitations. When the target system attempts to process these oversized packets, it may result in system instability or crashes.

HTTP Get/Post and Slowloris Attacks

HTTP GET/POST attacks and Slowloris attacks are both types of web-based attacks that exploit vulnerabilities in web servers and applications.

  1. HTTP GET/POST Attacks:

    • Overview: HTTP GET and POST are two common methods used for communication between a client (usually a web browser) and a web server. These methods are employed for various tasks, such as requesting and submitting data.
    • Attack Scenario: In an HTTP GET/POST attack, an attacker manipulates or exploits these methods to compromise a web application. This may involve sending crafted GET or POST requests with malicious input, attempting to exploit vulnerabilities in the application, such as injection attacks (SQL injection, Cross-Site Scripting, etc.).
    • Mitigation: Protecting against HTTP GET/POST attacks involves implementing input validation, using secure coding practices, and employing web application firewalls (WAFs) to filter and block malicious requests.
  2. Slowloris Attack:

    • Overview: Slowloris is a type of Denial of Service (DoS) attack specifically designed to target web servers. It was created to exploit the way web servers handle multiple concurrent connections.
    • Attack Scenario: In a Slowloris attack, the attacker establishes multiple connections to the target web server but sends the HTTP request headers very slowly, taking advantage of the fact that web servers typically keep connections open while waiting for the complete request. By sending requests slowly, the attacker can tie up available connections, preventing the server from accepting legitimate connections and causing a denial of service.
    • Mitigation: Mitigating Slowloris attacks involves implementing various measures, including setting shorter timeouts for idle connections, increasing the maximum number of allowed connections, and using rate-limiting mechanisms to detect and block suspicious patterns indicative of a Slowloris attack.

In summary, HTTP GET/POST attacks focus on exploiting vulnerabilities within the application layer, while Slowloris attacks target the web server’s handling of connections to cause a denial of service. Organizations should adopt a multi-layered security approach that includes secure coding practices, regular security audits, and the use of security mechanisms such as WAFs and rate limiting to protect against these types of web-based attacks.

Multi Vector Attacks

A multi-vector DDoS (Distributed Denial of Service) attack is a type of cyber attack that involves using multiple methods or techniques simultaneously to overwhelm and disrupt the targeted system or network. DDoS attacks are designed to flood a target with a large volume of traffic, making it difficult or impossible for the system to function properly, ultimately denying access to legitimate users.

Here are some common vectors that can be combined in a multi-vector DDoS attack:

  1. Volumetric Attacks: Overwhelm the target’s bandwidth with a high volume of traffic. This can include UDP (User Datagram Protocol) reflection/amplification attacks, where attackers use poorly configured servers to amplify their attack traffic.

  2. TCP State-Exhaustion Attacks: Exploit the stateful nature of TCP (Transmission Control Protocol) to exhaust the target’s resources by creating numerous half-open connections, consuming server resources and preventing it from handling legitimate requests.

  3. Application Layer Attacks: Target the application layer of the OSI model, aiming to exhaust server resources by exploiting vulnerabilities in web servers, databases, or specific applications. These attacks can be more challenging to mitigate because they often mimic legitimate traffic.

  4. DNS Amplification: Use DNS servers to amplify attack traffic. By sending small DNS queries with a spoofed source IP address, attackers trick DNS servers into sending larger responses to the target.

  5. SSL/TLS Attacks: Exploit vulnerabilities in the SSL/TLS protocols to consume server resources and bandwidth by initiating a large number of SSL/TLS handshakes.

  6. IoT-Based Attacks: Utilize compromised Internet of Things (IoT) devices to create a botnet and launch DDoS attacks. IoT devices often have weak security measures and can be easily enlisted in large-scale attacks.

By combining these attack vectors, cybercriminals aim to diversify their methods and overcome the specific defenses that might be effective against individual vectors. Defending against multi-vector DDoS attacks requires a comprehensive cybersecurity strategy, including:

  • DDoS Mitigation Services: Employing specialized services or appliances that can detect and filter out malicious traffic during an attack.
  • Network Traffic Monitoring: Using tools to continuously monitor network traffic for signs of abnormal or suspicious patterns.
  • Firewalls and Intrusion Prevention Systems: Configuring network devices to filter and block traffic based on predefined rules.
  • Rate Limiting: Implementing rate-limiting mechanisms to restrict the number of requests a system can handle within a specific timeframe.
  • Incident Response Planning: Having a well-defined incident response plan to quickly mitigate and recover from DDoS attacks.

Peer To Peer Attack

A peer-to-peer (P2P) DDoS attack is a distributed denial of service attack that involves a network of compromised devices (peers) working together to flood a target system or network with malicious traffic. In a traditional DDoS attack, a central command and control server may direct a botnet of compromised computers to launch the attack. In a P2P DDoS attack, the coordination among the attacking devices is decentralized, with each peer potentially communicating directly with other peers without a central server.

Here are key characteristics and considerations regarding peer-to-peer DDoS attacks:

  1. Decentralization: In a P2P DDoS attack, the communication and coordination between the compromised devices occur in a decentralized manner. This makes it more challenging for defenders to locate and mitigate the attack source.

  2. Botnets: The attacking network is essentially a botnet formed by compromised computers, servers, or IoT devices. Each device in the botnet, referred to as a peer, may contribute a portion of the attack traffic.

  3. Resilience: P2P DDoS attacks can be more resilient than attacks with a centralized command and control structure. If one peer is identified and taken down, the other peers may continue the attack independently.

  4. Difficult Attribution: Due to the decentralized nature of P2P DDoS attacks, identifying the original source of the attack traffic can be more challenging. Attackers may use various techniques, such as IP spoofing, to hide their true locations.

  5. Varied Attack Vectors: P2P DDoS attacks can involve various attack vectors, including volumetric attacks (flooding the target with a high volume of traffic), application layer attacks (targeting specific applications), and other methods.

Permanent DoS or Phlashing Attack

“Phlashing” refers to a type of cyber attack that involves rendering a device or system inoperable by corrupting the firmware or hardware. The term “phlashing” is derived from “phreaking” (the manipulation of phone systems) and “flashing” (referring to updating firmware). In the context of a DDoS (Distributed Denial of Service) attack, phlashing is used to describe a method where attackers aim to permanently damage or “brick” a device by overwriting or corrupting its firmware so that the victim should replace or reinstall the hardware.

Here are key points about phlashing in the context of a DDoS attack:

  1. Firmware and Hardware Damage: Phlashing attacks focus on causing permanent damage to the firmware or hardware of a device, such as routers, switches, or other networked equipment.

  2. Long-Term Impact: Unlike traditional DDoS attacks that aim to disrupt services temporarily, phlashing attacks seek to render the target device permanently unusable. This can lead to significant financial losses and downtime for the affected organization.

  3. Exploiting Vulnerabilities: Phlashing attacks often exploit vulnerabilities in the firmware or software of the targeted devices. This may involve exploiting security flaws, unauthorized firmware updates, or other methods to compromise the integrity of the device.

  4. Difficult Recovery: Recovering from a phlashing attack can be challenging, as it requires reprogramming or replacing the damaged firmware or hardware. In some cases, recovery may not be possible, resulting in the need for hardware replacement.

It’s important to note that while traditional DDoS attacks focus on overwhelming a target with a high volume of traffic, phlashing attacks have a distinct goal of causing long-term damage by specifically targeting the device’s firmware or hardware.

TCP SACK Panic Attack

A TCP SACK panic attack is a type of denial-of-service (DoS) attack that exploits vulnerabilities in the TCP (Transmission Control Protocol) stack, specifically the Selective Acknowledgement (SACK) mechanism, to crash or overwhelm targeted systems.

Here’s a breakdown of the key elements involved:

  • TCP: This is the fundamental protocol that governs communication over the internet, ensuring reliable data transmission by sequencing and acknowledging packets.
  • SACK: This is an optional TCP feature that allows receivers to acknowledge not just the next expected packet but also any subsequent packets they have successfully received. This helps in efficient retransmission of lost or out-of-order packets.
  • Vulnerability: The vulnerabilities exploited in a TCP SACK panic attack lie in the way the receiving system processes SACK packets, particularly when combined with specific settings like Maximum Segment Size (MSS). By sending carefully crafted SACK packets, attackers can trigger memory overflows, resource exhaustion, or even system crashes.

Distributed Reflection Denial-Of-Service Attack

A Distributed Reflection Denial of Service (DRDoS) attack is a type of cyber attack in which an attacker leverages multiple systems to generate and amplify a flood of requests to a target, overwhelming its resources and causing a denial of service. The “reflection” part of the term refers to the attacker’s use of third-party systems to generate and amplify the attack traffic. This attack involves use of multiple intermediary and secondary machines that contribute to the actual DDoS attack.

Here’s how a Distributed Reflection Denial of Service (DRDoS) attack typically works:

  1. Amplification Technique: The attacker sends requests to a large number of vulnerable or misconfigured servers (often using protocols like DNS, NTP, SNMP, or SSDP). These servers, which are referred to as reflectors, respond to the requests and inadvertently amplify the traffic sent to the target.

  2. Spoofing the Source IP Address: The attacker usually spoofs the source IP address in the requests to make it appear as if the requests are coming from the target. This makes it challenging for the target to filter out the malicious traffic.

  3. Target Overwhelmed: As a result, the target receives a massive volume of amplified traffic from the reflectors, far exceeding its capacity to handle requests. This can lead to network congestion, service degradation, or complete unavailability.

  4. Distributed Nature: Like other DDoS attacks, a DRDoS attack is distributed, meaning it involves multiple systems (often a botnet) working together. This distributed nature makes it more challenging for defenders to mitigate the attack by blocking a single source.

  5. Amplification Factors: The amplification factor is a crucial aspect of DRDoS attacks. It measures how much the attack traffic is amplified compared to the initial requests sent by the attacker. The higher the amplification factor, the more effective the attack.

DDoS Extortion

DDoS extortion is a cybercrime tactic where an attacker threatens to launch a Distributed Denial of Service (DDoS) attack against a target unless a ransom is paid. In these scenarios, the attacker typically claims that they have the capability to flood the target’s network, servers, or online services with a massive volume of traffic, rendering them unavailable to users.

Here’s how DDoS extortion typically unfolds:

  1. Threatening Communication: The attacker contacts the target, often through email or other electronic means, and claims that they possess the resources and capability to launch a significant DDoS attack.

  2. Ransom Demand: The attacker demands a ransom payment, usually in cryptocurrency, to be paid within a specified timeframe. The threat is that if the payment is not made, the attacker will initiate the DDoS attack, causing disruption to the target’s online services.

  3. Demonstration of Capability: In some cases, the attacker may provide a demonstration of their DDoS capability by launching a smaller-scale attack or providing evidence of previous successful attacks.

  4. Impersonation: Attackers may use various tactics to mask their identity, such as using anonymizing tools or presenting themselves as a hacking group with a history of successful attacks.

Organizations facing DDoS extortion attempts need to carefully assess the threat and determine an appropriate response. Here are some recommended actions:

  • Do Not Pay the Ransom: It is generally advised not to pay the ransom. Paying does not guarantee that the attacker won’t return with additional demands, and there’s no assurance that they will stop the attack even if the ransom is paid.

  • Communication and Reporting: Organizations should communicate with law enforcement and report the extortion attempt. Local law enforcement agencies and cybersecurity authorities may be able to provide guidance and assistance.

  • Prepare for DDoS Mitigation: Have a DDoS mitigation plan in place. This may include working with a DDoS mitigation service provider to quickly detect and mitigate DDoS attacks when they occur.

  • Monitor Network Traffic: Implement monitoring tools to detect unusual or suspicious network traffic patterns that may indicate a potential DDoS attack.

  • Enhance Security Measures: Strengthen overall cybersecurity measures, including firewalls, intrusion prevention systems, and access controls, to minimize the impact of potential DDoS attacks.

It’s important for organizations to be proactive in securing their online presence and to have incident response plans in place to effectively handle various cybersecurity threats, including DDoS extortion attempts.

DDoS Attack Tools

High Orbit Ion Cannon (HOIC) and Low Orbit Ion Cannon (LOIC), XOIC, HULK, Metasploit, Tor’s Hammer, Slowloris and PyLoris are some of the DDoS attack tools.

DDOS Attack Countermeasures

Protect Secondary Victims

In a DDoS attack, secondary victims are often innocent parties whose systems or networks are used to launch the attack. To protect them, it’s essential to implement measures that prevent their systems from being exploited. This can be achieved by:

  • Implementing robust security measures, such as firewalls and intrusion detection systems, to prevent unauthorized access to systems and networks.
  • Keeping software and systems up-to-date with the latest security patches to prevent exploitation of known vulnerabilities.
  • Educating users about the risks of DDoS attacks and the importance of security best practices.

Detect and Neutralize Handlers

Handlers are the compromised systems or devices that are used to launch DDoS attacks. To detect and neutralize handlers, organizations can:

  • Implement advanced threat detection systems that can identify suspicious traffic patterns and anomalies.
  • Use honeypots and honeynets to detect and trap malicious traffic.
  • Collaborate with other organizations and law enforcement agencies to share threat intelligence and take down handler systems.

Prevent Potential Attacks

Preventing potential DDoS attacks requires a proactive approach to security. Organizations can:

  • Implement robust security measures, such as firewalls and intrusion prevention systems, to prevent unauthorized access to systems and networks.
  • Conduct regular security audits and penetration testing to identify vulnerabilities and weaknesses.
  • Implement rate limiting and IP blocking to prevent excessive traffic from reaching systems and networks.

Deflect Attacks

Deflecting DDoS attacks involves redirecting or absorbing the traffic to prevent it from reaching the targeted system or network. This can be achieved by:

  • Implementing content delivery networks (CDNs) that can absorb and distribute traffic across multiple nodes.
  • Using cloud-based DDoS mitigation services that can scale to handle large volumes of traffic.
  • Implementing traffic filtering and scrubbing techniques to remove malicious traffic.

Mitigate Attacks

Mitigating DDoS attacks involves reducing the impact of the attack on the targeted system or network. This can be achieved by:

  • Implementing load balancing and traffic management techniques to distribute traffic across multiple systems and networks.
  • Using caching and content optimization techniques to reduce the load on systems and networks.
  • Implementing quality of service (QoS) policies to prioritize critical traffic and limit the impact of the attack.

Post-attack Forensics

After a DDoS attack, it’s essential to conduct a thorough forensic analysis to identify the source of the attack, understand the tactics and techniques used, and improve defenses. This can be achieved by:

  • Collecting and analyzing network logs and traffic data to identify the source of the attack.
  • Conducting a thorough incident response process to identify vulnerabilities and weaknesses.
  • Implementing lessons learned from the attack to improve defenses and prevent future attacks.

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