Distributed Denial Of Service (DDOS) is the intentional paralyzing of a computer network by flooding it with data sent simultaneously from many individual computers (so-called zombies) which are used to stage DDOS attacks

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Finding the method of attack [closed]

My server has been repeatedly attacked in the last few days. Here's the observations: The ISP server traffic monitor shows the incoming traffic goes up to 300Mbps (with no outgoing traffic), and ...
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1answer
394 views

Are voluntary / manual DDoS illegal?

Since DDoS is simply a group of subjects coming together to send requests to a particular server, is it true to say that a voluntary DDoS is perfectly valid and legal in US? By that, I mean that a ...
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Analysing server (VPS) before hosting a government website [closed]

Hosting a government website would definitely increase reputation, but it would also bring higher chances of the hosting server getting attacked by DDoS attacks. It's a cPanel based VPS. What basic ...
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2answers
1k views

DDoS — null route everything not approved

Is it possible to create a route on your internet router which routes traffic unknown to null. So you basically dont even let traffic route into your firewall unless its approved? Can this help detour ...
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2answers
655 views

A DDOS attack by uploading a few hundred large files - whats stopping anybody?

I am new to the IT Security field and am essentially a developer as opposed to a networking person hence the question may be a dumb one I am writing a REST service exposed to the internet which ...
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4answers
3k views

Find out how my server is being used for DDOS attacks

I got an email from Amazon that my Amazon EC2 server is being used for DDoS attacks and they have closed all ports except SSH. This is tragical for me but I have not been able to find out how and ...
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3answers
753 views

SSL vs TLS, which is less vulnerable to DOS attacks?

When I learned TLS does not allow a connection to be created until it is has finished a secure handshake, i figured that would make it better for preventing DoS attacks. However, all I seem to find ...
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5k views

Why can we not block DNS Amplification attack by blocking UDP packets or DNS response packet?

I mean if the attacker tries to ask all the open DNS resolver respond to a web server. The web server can just block its UDP ports. If the all the DNS response go to a Authoritative ...
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Lessen impact of DoS attack on cpu-expensive login?

This is a follow-up to my previous question: Prevent DOS against RSA authentication. This question is also discusses a similar problem: Prevent denial of service attacks against slow hashing ...
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1answer
338 views

Spoofed DDoS mitigation / DNS amplification mitigation [duplicate]

Recently my server has been attacked multiple times, after looking at my firewall I've come to the conclusion that the IP's are spoofed. (10,000+ IP's connect at once) I'm running Win server 2012 x64 ...
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271 views

Are latency based Proof-of-Work systems capable of preventing DDoS attacks on popular hidden tor services (.onion websites)?

I was reading an interesting article found here: http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-703.pdf It's titled "Lazy Susan: dumb waiting as proof of work". It suggested the following in section ...
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Is anything written in the book “Internet Denial of Service: Attack and Defense Mechanisms” c2004 still valid? [closed]

I was reading through some of this book on google: http://books.google.ca/books?id=qmdCs_Jf2AEC It is uploaded to a hungarian website here: http://denialofservice.uw.hu/index.html I was reading... ...
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DoSing my Home Network with only a Public IP address [closed]

+--------------------------------------------------------+ | Client Host Name |.. IP Address ..|.... MAC Address ...| | Desktop-Home ....| 192.168.1.100 | 00:19:D1:EA:03:68 | | GT-S5380K ...
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3answers
11k views

Stopping DDOS TCP SYN and UDP flood attacks

I would like to know if it's possible to stop a TCP SYN OR ICMP Flood attacks if these attacks are detected at time. What is the most accurate process to filter these addresses if the only way is to ...
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1answer
129 views

Botnet Attempting to Login to Website

Our server has recently become a target of what appears to be a botnet attack. The first indication was an insane amount of traffic to one of our client's websites - so heavy that the server entirely ...
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7answers
13k views

DDoS - Impossible to stop?

Is it possible - in theory - to stop1 a DDoS attack of any size? Many people claim it's impossible to stop DDoS attacks and tell me I just shouldn't mess with the wrong people on the internet. But ...
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5answers
1k views

I have a client that is worried about DDOS attacks on their site, and they want penetration testing. Will that help?

My client wants to look into hiring a third party to perform penetration tests on the website that we're developing for them. The website is just a simple 3-month contest site where people can upload ...
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3answers
5k views

DNS Amplification DDOS attack

During the weekend I made some tests to simulate an DNS Amplification DDOS attack. sending about 90Mb/s traffic I was able to generate about x.x Gb/s amplified traffic which sent our datacenter ...
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7answers
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Would it be possible to overload a large part of the internet, and if so then how?

Last week a news article went viral about a Dutch web hosting/data center company that was allegedly using a DNS amplification attack to DDoS an anti-spam company, because they blacklisting the ...
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3answers
2k views

How will IPv6 affect DDoS mitigation techniques?

IPv6 introduces a much larger address space than IPv4 and with it there are many new techniques in creating and mitigating DDoS attacks. What are some examples of risks and mitigations? For example, ...
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1answer
508 views

DDoS prevention (LOIC doesn't do the job anymore) [closed]

We are about to launch a important webservice. We must test it for DDoS. From other questions/answers here I learned about LOIC. Downloaded, tried, but my apache refuses it. What other ready made ...
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0answers
191 views

Snort Parallelization Techniques and its effect on DDOS detection capability

I want to ask a query about snort parallelization. 1) Can snort detection rate remains same for all attacks after parallelisation? 2) As the parallelisation of netowrk traffic in each core is based ...
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3answers
1k views

Why is it easy to detect network layer DDoS attacks?

I have seen numerous research papers that claim it is "easy to detect network layer DDoS attacks" without saying why. Usually these research papers focus on detection or prevention of application ...
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151 views

DDOS protection for instant messenger server

I developed an instant messenger which uses TCP ports for its communication, and hosted the server application on a VPS account from some hosting company, but the first day I got attacked by a ...
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2answers
827 views

How to mitigate SIP Reflection Attacks?

SIP has a practical need to be widely available, but its services are prone to being spoofed as reflectors used in DDoS attacks. A freeswitch server I manage has seen heaps of registration requests ...
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How to Secure a Stream from DDoSers?

I conduct a weekly live-stream using Google Hangouts that streams over YouTube. Recently, the stream has been attacked by DDoSers. In an attempt to thwart such attacks, I have tried to keep my IP ...
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how to mitigate a DDoS from botnet on your website that comes from random IPs

I am wondering how do you mitigate a ddos attack which is coming from a botnet and hitting random URLs on a website. If there was a consistent URL it was hitting then it would be fairly simple, and ...
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3answers
122 views

Where is the limit between an attacker and a victim (zombie) in a DDoS attack

Let's say that A is DDoSing B and I'm a member of his botnet. Who says that I'm not a real attacker but a victim? How you determine it?
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766 views

unknown MAC address in the LAN, DD-WRT router

I am using a linksys router with DD-WRT firmware with a WiBro internet connection, the ISP uses a hub with multiple user connected to it. The issue is that an unidentified MAC address seems to pop up ...
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6answers
567 views

Bot detecting by considering request inter-arrival time

If there are some chances to detect a bot by considering the users page viewing time, is it possible to measure this time? When a user request for a page (page request), browser request for several ...
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3answers
314 views

How similar are bots regarding their HTTP GET request?

Lets assume a botnet is attacking a website by HTTP GET flooding. To find the bots, the only way seems to be finding the similarities of the HTTP GET requests considering the URL and header fields, ...
4
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1answer
596 views

Creating a DDoS attack using DirectConnect

I have been trying to hack around with Apex DirectConnect. What I wish to do is to utilize the querying nature of P2P apps like DC to generate a DDoS attack (see links for reference here, here and ...
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How can I identify open DNS resolvers in my network?

This article highlights how open DNS resolvers are being used to create DDOS attacks across the internet. How can I identify whether any of our DNS servers are open? If I find that we are running ...
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3answers
1k views

DDoS on LAN: How to Defend?

DDos on a wired network has to be extremely rare, since the intruder has to be physically connected to the network. However, let's say that it still managed to happen. How would you be able to defend ...
6
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1answer
179 views

Parabolic Denial Of Service — Would it work?

Would this DoS attack be effective: Attacker determines target (10.0.0.1) Attacker sends ack packets to a buch of web servers with a src addr of 10.0.0.1 Servers reply to 10.0.0.1 with syn packets ...
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How does CAPTCHA mitigate DDoS attacks?

This seems like an easy question, but I've failed to find an answer. One of the uses of CAPTCHA is to cope mitigate Denial of Service attacks. Suppose an adversary performs excessive login attempts, ...
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5answers
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What is a DoS Attack and how does it differ from a DDoS attack?

Can some one explain to me the concept of Dos Attacks for web applications ? Also what is the distinction between Dos and Distributed Dos ( ie DDos) attacks ? Wikipedia says : In computing, a ...
2
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2answers
278 views

Can an attacker slow down my server without compromising it?

We have a Linux server with WHM/cPanel which has been running without problems for almost 3 years now. Yesterday, the server became unresponsive (it was definitely there though) for around an hour. ...
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3answers
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How to protect myself against paid DDoS services?

I am domestic user and I am getting attacked regularly by a guy that hates me. Here is the background story: that guy uses Skype resolvers (tools offered by paid DDoS services) to find out my IP ...
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4answers
671 views

Global Blackout is a myth?

In order to shut the Internet down, anonymous claimed that putting-down the 13 root DNS servers of the Internet and therefore disabling the HTTP Internet, the most widely used function of the Web, ...
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4answers
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mitigating anonymous DOS (tor combined with pyloris)

I found this rather scary video in youtube, that takes DOS to a whole new level, by making it look like coming from multiple sources. As a counter measure to Rsnake (Robert Hansen) slowloris.py ...
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1answer
822 views

My server is being DDoS'ed with 13 gbit and my provider nulled my ip, taking down my server - what can i do [duplicate]

Possible Duplicate: How can a Software application defend against DoS or DDoS? Accessing a site (which is) under a DDoS Null-routed IP 85.17.154.139 8/5/12 In progress 13Gb ddos ...
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3answers
222 views

Denial of Service on SSL services

When the SSL handshake takes place, is there a point where the computational work done by the client is significantly less than the computational work done by the server? Could such an imbalance be ...
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1answer
963 views

Monitor incoming TCP/UDP flood attack and graph it

I'm preparing a presentation on a security issue and want to include a demonstration. It won't be in real time, I just need to show some pictures of the results. I have some VPSes that will perform a ...
2
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2answers
3k views

IPTables DDoS protection working with per client IP address counter AND UDP

I am looking to protect LAMP server with a software, which will detect above average number of requests from single IP numbers (in this case DNS queries), and add these hosts to IPTables deny chain. ...
2
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2answers
2k views

DDoS Protection for DNS providers

Zerigo, our DNS provider has reported to have been under heavy DDOS attack in the last 24 hours or so. Considering the distributed nature of DNS, and their architecture consisting of 5 main DNS ...
2
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1answer
124 views

Types of attacks outside of AppSec and Vendor-Specific Systems?

I'm reading up on the OWASP Top 10 for helping me defend my web app against common "app sec"-type attacks (SQL Injection, CSRF, etc.). And in a recent question I was prompted to not only use OWASP Top ...
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4answers
1k views

Spider Attack from several search engines at once

Hello my server is getting hit by spiders from bingbot, google, yahoo, yandex, and some place in the UK all at the same time crashing it. While I have no reason to think any one person did this, it ...
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2answers
96 views

Looking for information about CVE-2006-6876 vulnerability

In order to study vulnerabilities of a SIP server and the impacts of DOS attacks on the QoS of VoIP service, I have found this vulnerability which can be exploited to cause DoS on SIP server. But I ...
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1answer
683 views

Linux tools to choose suitable Cisco ASA 5500

I have a linux webhosting server which affects a high DDOS. I want to use Cisco ASA 5500 Series Adaptive Security Appliances to protect the linux server from this DDOS. I know there are many factors ...