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Security Architecture

MIS 5214 - Section 001 - David Lanter

Security Architecture

MIS 5214.001 ■ Spring 2023 ■ David Lanter
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    • First Half of the Semester
      • Unit 01 – Threat Environment
      • Unit 02 – System Security Plan
      • Unit 03 – Planning and Policy
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      • Unit 05 – Secure Networks
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      • Unit 08 – Access Control
      • Unit 9 Host Hardening
      • Unit 10 Application Security
      • Unit 11 Data Protection
      • Unit 12 – Incident and Disaster Response
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      • Case Study 1 – A High Performance Computing Cluster Under Attack: The Titan Incident
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An Introduction to DDoS Distributed Denial of Service Attack

February 8, 2023 by David Lanter 25 Comments

Filed Under: 05 - Secure Networks Tagged With:

Reader Interactions

Comments

  1. Asha Kunchakarra says

    February 10, 2023 at 10:12 am

    DDoS are difficult to detect and mitigate because often times they are no fixed IP addresses or the IP addresses of the zombie computers that connect to the interest using broadband connections. Sometimes the IP addresses are spoofed as well. This causes many issues because people are not able to detect what is real and what is fake, leading to difficulties in mitigating the issue. However there are some techniques that have been established to try and mitigate the risk which include identification of statistical patterns to filter illegitimate traffic or having alternate network paths with load balancing.

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    • Chinenye Marylyn Akinola says

      February 11, 2023 at 5:30 am

      Good point Asha! In addition, the DNS servers become overloaded by zombie computers using the victim server’s spoof IP address during a DDoS assault. All of these zombie computers query the DNS server at once, using up all of the victim server’s bandwidth as the DNS server tries to respond.

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  2. Aayush Mittal says

    February 10, 2023 at 12:21 pm

    It was interesting the way the attack was explained with the example in the reading. A ‘Syn’ Flood attack targets applications. It opens multiple connections (using multiple zombie computers) to the victim server using ‘Syn’ requests. The server responds with ‘Syn-Ack’ acknowledgement. The zombie computers need to send back an ‘Ack’ response, for the victim server to close the connection. But they don’t do that, resulting in many open connections in the server, which cannot be used by other users.

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    • Sunam Rijal says

      February 11, 2023 at 8:06 am

      Hi Aayush,
      The example provided in the reading about a ‘Syn’ Flood attack is indeed interesting and informative. It helps in understanding the working of this particular type of DDoS attack, which targets applications and can potentially cause a lot of damage to the victim server. By opening multiple connections to the victim server using ‘Syn’ requests and not responding with an ‘Ack’ response, the attacker can overwhelm the server with a large number of open connections, rendering it unavailable to other users. This highlights the importance of implementing proper security measures to protect against DDoS attacks and to ensure the availability and reliability of network resources.

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  3. Nishant Shah says

    February 10, 2023 at 8:44 pm

    While the DDoS attacks primarily affect the availability of resources it was interesting to know that there are two kinds of DDoS attacks. One affects the network availability and the other affects the computational resource availability by exploiting application vulnerabilities. While the article lists a few steps to prevent the DDoS attack it is crucial to protect the zombie computers so they don’t get infected in the first place and become part of a large DDoS botnet.

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    • Wei Zhang says

      February 13, 2023 at 10:30 pm

      Hi Nishant,
      While protecting zombie computers from being manipulated can destroy DDoS mid-stream, the article also notes that most of the time infected computers unknowingly become zombie computers controlled by the attacker to overwhelm the attacked server. My question is, does the zombie computer have a way to determine if it was controlled?

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      • Nishant Shah says

        February 15, 2023 at 2:24 am

        Hello Wei! I believe it is possible to detect if a computer is being used as a zombie by looking for unauthorized egress traffic on the network. I would think that the indicators of infection would be high CPU utilization and network bandwidth utilization.

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  4. Chinenye Marylyn Akinola says

    February 11, 2023 at 5:11 am

    The reading helped me understand why DDoS attacks are challenging to identify and counter. According to this article, the attacker conducts attacks against the victim server using the machines of unwitting users, making it challenging to identify who is responsible. One of the strategies identified as a tool for reducing DDos assaults is the use of honeypots, which lure hackers into a trap. It essentially functions as a decoy for cyberattacks. Setting up mock servers with the greatest number of vulnerabilities exposes them to hackers as legitimate servers. It is feasible to examine attack patterns, attack goals, and even assault sources when hackers attack these systems.

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    • Aayush Mittal says

      February 13, 2023 at 10:14 pm

      Hi Marylyn, yeah HoneyPots is indeed a very interesting technique which involves the setting up of dummy servers that are exposed to hackers as legitimate servers. However, I have seen that most of the organizations do not use or set up this technique until it’s a regulatory requirement.

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  5. Sunam Rijal says

    February 11, 2023 at 7:57 am

    A Distributed Denial of Service (DDoS) attack is a type of cyber-attack where a large number of infected computers, also known as “zombies”, are used to flood a targeted server with a huge amount of information to prevent legitimate users from accessing it. A DDoS attack is difficult to detect and mitigate due to the use of unsuspecting user’s computers and the lack of fixed IP addresses for zombie computers. There are two types of DDoS attacks: those that target the network and choke the Internet bandwidth, and those that target application vulnerabilities to cripple server resources. Some measures to prevent/mitigate DDoS attacks include identification of statistical patterns of the attack, filtering illegitimate traffic, using appropriate hardware/software solutions, and having a backup plan in place.

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  6. Pranavi Yadalam Sekhar says

    February 11, 2023 at 11:24 am

    It is a form of attack where a lot of zombie computer directly/ indirectly attack the server. According to DDoS architecture diagram it having 5 components, 2 components which is first and last is attackers components and middle three are victim server which is ready to get attacked. DDoS is difficult to detect and mitigate because there is no fixed in address . Attacks are in multiple gigabits per second.There are two types of DDoS attacks : attacks that target the network , choke the internet bandwidth .
    Steps for mitigation of DDoS :
    Identification of patterns
    Having a alternative paths
    Throttling
    Honeypots
    Aggressive caching

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    • Shepherd Shenjere says

      February 12, 2023 at 12:23 pm

      Hello Pranavi,

      Great points Pranavi. Just to add to two types of DDoS that can be carried out against an organization. Another one that has been mentioned in the article is Attacks that target the vulnerabilities in applications in order to cripple server resources like CPU, RAM, Buffer memory, etc and make the servers unavailable for handling any legitimate requests. So, its a duty for security personnel’s to perform periodical scans checking for open vulnerabilities that may require patching and handle them accordingly.

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  7. Mengqi Xiong says

    February 12, 2023 at 10:51 am

    Distributed Denial of Service (DDoS) attacks use multiple compromised computers to inject traffic into a target system, rendering it unusable by the intended users. DDoS attacks require a large number of systems to carry out the attack, often with the help of botnet attackers. Different types of DDoS attacks include attacks based on network traffic (Internet bandwidth) or attacks on the application layer or hybrid attacks. DDoS attacks can cause severe damage and disruption and are difficult to defend against. Organizations can implement measures to help defend against DDoS attacks, such as Rate-Limiting/ Throttling and Honeypots. If an attack is detected, the rate-limiting system may lower the rate limit, making it more difficult for the attacker to overwhelm the target system. Honeypots can trap and analyze attacks by designing a “target” that resembles a real system and mimics the behavior of the native system to lure attackers into attacking them.

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  8. Shepherd Shenjere says

    February 12, 2023 at 12:12 pm

    Distributed Denial of Service (DDoS) is one of the most commonly tactic used by cybercriminals to attack an organization’s network or vulnerabilities that exist in different applications. The article indicated that DDoS can be very difficult to detect and even implement controls that mitigates it. However, certain measures can be taken to safeguard the organization against attacks of this magnitude. The article described steps that can be taken to prevent or mitigate it. I found it very fascinating because it puts an organization in a better position to fight or protect against DDoS. They include identification of statistical patterns, having alternate network paths and applying load balancing, Rate-Limiting/ Throttling, Honeypots which many organization do not usually use it, Aggressive Caching, and host websites on cloud infrastructure.

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    • Abayomi Aiyedebinu says

      February 12, 2023 at 3:36 pm

      Hi Shepherd,

      I agree with you that DDOS attack can be difficult to detect because unsuspecting user’s computers are used as zombies to carry out the attack against a victim server which makes it difficult to trace the actual attacker.

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  9. Jill Brummer says

    February 12, 2023 at 2:01 pm

    I found it helpful that the reading provided several steps to prevent and mitigate Ddos attacks. Some of the steps are Identify statistical patterns, having alternate network paths, throttling (which is controlling the maximum incoming traffic, honeypots (dummy servers), aggressive caching, and protect the zombie computers (ensure they can’t get infected by attackers).

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  10. David Vanaman says

    February 12, 2023 at 3:14 pm

    The concept of the DDoS is one of the oldest attacks on networks that I can recall that is still common. Over the decades since the first ping-flood or syn flood attacks were classified as DDoS attacks, there have been improvements in networking architecture, firewalls, and zombie/bot detection, but the number and size of DDoS attacks continues to grow. It is only inevitable, as more and more devices are added to the internet, it only takes a fraction of a percent of them to be vulnerable to build a botnet. Cloud infrastructure and services like Cloudflare are helping by allowing systems to soak up huge amounts of malicious incoming packets before suffering denial.

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  11. Abayomi Aiyedebinu says

    February 12, 2023 at 3:34 pm

    A DDoS attack occurs when a threat actor uses resources from multiple, remote locations to attack an organization’s online operations. Usually, DDoS attacks focus on generating attacks that manipulate the default, or even proper workings, of network equipment and services. An interesting thing to note is that unsuspecting user’s computers are used as zombies to carry out the attack against a victim server which makes it difficult to trace the actual attacker.

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  12. Nicholas Foster says

    February 12, 2023 at 5:25 pm

    One of the most fascinating things about DDoS attacks in my opinion is the usage of Botnets. Botnets are a collection of private computes infected with malicious software that can be controlled in unison to perform attacks all without the owner of the device knowing it’s happening. It’s nearly the perfect crime in that you get other machines to do the attack for you. Botnets can be millions of PC’s coming from all over the globe making it nearly impossible to trace/detect the source. simultaneously, making it harder for those combating it to filter legit requests from malicious ones. Now adays you don’t even need to disseminate the malicious software; you can just pay someone who’s already done it to do your bidding. Monetizing the service, essentially DDoS-for-hire. It’s gone as mainstream as naming these people booters or stressers.

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  13. Frank Kofi Kpotivi says

    February 12, 2023 at 8:02 pm

    My main takeaway from this reading was that there are two different kinds of DDoS attacks. As the article explains, there are attacks that target vulnerabilities as well as the network and saturate the targeted server’s Internet bandwidth, preventing it from accepting user requests over the Internet gateway.

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  14. Wei Zhang says

    February 12, 2023 at 8:35 pm

    The denial of service (DOS) attack consists of the attacker/host computer and the victim/attacked server. Distributed denial of Service attacks (DDoS) increases the number of zombie computers used to perform the attacks. Because zombie computers with broadband connections do not have fixed IP addresses, attackers can always summon more computers even if they identify and intercept some of the attacking zombie computers, making DDoS difficult to predict and mitigate. Prevention/mitigation DDoS steps given in the article:
    Identify statistical patterns of DDoS attacks and compare them to real-time traffic
    Having alternate network paths and applying load balancing to incoming traffic reduces the risk of DDoS attacks
    Rate limiting/throttling
    Honeypots
    Aggressive Caching
    Hosting on cloud infrastructure/content delivery networks/managed service provider etc

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  15. Elizaveta Ibeme says

    February 12, 2023 at 10:35 pm

    An interesting point about denial of service attacks is that if the attacker decides to use multiple master computers and sends less number of attacks from each, they will have a higher chance of success.

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    • Nishant Shah says

      February 13, 2023 at 12:22 am

      That is true! And, building on that fact these days it is possible to obtain DDoS as a Service! A customer can find a botnet owner on dark web and pay to use DDoS as a Service. Botnet owners maintain an automated system of orders allowing buyers to select the type and duration of the attack, and transfer money to the perpetrator.
      There is no personal contact between the cybercriminals and clients, ensuring a high degree of anonymity. Some DDoSaaS providers offer discounts and loyalty programs to regular clients.

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  16. Shadrack Owusu says

    February 14, 2023 at 10:40 am

    One of the steps for the prevention/ mitigation of Distributed Denial of Service attacks (DDoS) is aggressive Caching. Caching is a method by which the frequently accessed web pages are stored as separate HTML files and when users request these pages, the HTML files are presented to them instead of the Time/CPU resource-consuming database queries. The benefits of caching are decreased network costs, Availability of content during network interruptions, and improved responsiveness.

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  17. Samuel Omotosho says

    February 25, 2023 at 12:56 pm

    It was fascinating to see that DDoS attacks are classified into two types: those that attack the network and those that target software vulnerabilities. Also, seeing that DDoS attacks are difficult to prevent and mitigate it was intriguing to observe the various methods that can be used to mitigate these attacks. I believe that conducting a honey pot experiment would be eye-opening for many organizations because it would allow them to gain statistical patterns and attack intentions, as stated in the article, allowing them to be better prepared if they were to experience a DDoS attack on their daily servers.

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Weekly Discussions

  • 01 – Introduction (1)
  • 01 – Threat Environment (3)
  • 02 – System Security Plan (6)
  • 03 – Planning and Policy (7)
  • 04 – Cryptography (4)
  • 05 – Secure Networks (7)
  • 06 – Firewalls (5)
  • 08 – Access Control (7)
  • 09 – Host Hardening (5)
  • 10 – Application Security (5)
  • 11 – Data Protection (3)
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