Questions tagged [ddos]

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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1answer
106 views

How to setup a shell account provider? [closed]

I want to provide ssh/shell access to one server, is similar to what you can find here https://shells.red-pill.eu/. what should i keep in mind before giving access? I was thinking on * cgrups (...
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2answers
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DDoS attacks on SSL/TLS [duplicate]

Upon receiving a ClientHello message, most of the time a web server (and without authenticating the client) performs a diffie-hellman exponential modular operation to compute and save the f = g^a mod ...
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3answers
755 views

Why are DDos-Attacks still possible?

There are so many Intrusion Detection Systems and systems that block IP Addresses with suspicous behavior. Everyone can use those systems, as many of them are free. But why is it then still possible ...
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1answer
147 views

Could a dynamic security system prevent DDoS attacks?

I don't know much about security, but here's what I think I understand about my question, at a high level: DDoS attacks are caused by a LOT of network traffic, which can be hard to mitigate because ...
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1answer
111 views

Is dns ddos protection enough for my website ddos protection?

If I hide my server's public IP and using a DDoS protection service such as CloudFlare or DYN, does it means that my website is safe from DDoS attacks? Or can an attacker conduct DDoS attacks that ...
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1answer
727 views

Does this look like a DDOS attack?

I've put up a small proof of concept web api on AWS infrastructure (elastic beanstalk) using their free tier. My app is working fine, but I'm seeing a lot of this in the access logs: 172.xxx.xxx.xxx -...
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1answer
605 views

How Can I Tell If A Denial-Of-Service Attack Is Working/Would This Attack Work? [closed]

Say I want to test the security of a site and I decide to send a DOS attack against it using a javascript script: function imgflood(link, uri) { var TARGET = link; var URI = uri; var pic =...
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1answer
95 views

DDos prevention systems behavior for corporate networks [closed]

I asked this question on stackoverflow but couldn't get any answers and I even got a down vote as a present so that I'll try my luck out here. I did some research about this problem and couldn't find ...
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1answer
180 views

What Kind of Site Would I Need To DDOS

Recently I heard about Distributed Denial of Service and Denial of Service attacks and to see how this worked, I made a quick script (this is not a debug thing, I have an actual question about Cyber ...
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1answer
79 views

How can websites with URL traversal functionality protect itself from revealing its IP?

A good number of websites these days are not served directly over the internet, but through an intermediate providers, such as Cloudflare and Incapsula. A basic premise of the security provided by ...
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2answers
976 views

Why is IP spoofing still possible?

What are valid usages? Why don't ISPs prevent this by default? Do any major ISPs do this already?
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1answer
310 views

Slash and dash DDOS - what are they trying to do?

I've noticed a curious flood pattern on some of my sites - bots trying to access the page ​"/-​/-​/-​/-​/-​/-​/-​/-​/-​/-​/" on the root domain - that's 11 slashes alternated by 10 dashes. The thing ...
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5answers
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Cloud-based DDoS as a Service

With the consolidation of cloud computing and virtualization, a really simple doubt comes to my mind: why isn't DDoS being largely offered as a service? Why don't we see cloud-based DDoS attacks? ...
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2answers
713 views

Beginner-friendly tool to simulate HTTP flood on my website

Is there any easy-to-use tool available I can use to produce an HTTP GET flood on a website I maintain? If so, can you also explain in steps how to use it? I need to do this for testing purposes. Our ...
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2answers
146 views

Does the choice of protocol affect the efficiency of a DOS attack?

I was wondering, to make a DOS attack you need to send something to the target you are DOS-ing. And to send something you need to use some protocol. My question is, are all protocols the same speed? ...
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4answers
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What is the website checking about my browser to protect the website from a DDoS?

Some sites I visit take me to a page that says roughly, "Checking your browser before accessing example.com. DDoS attack protection by CloudFlare". What exactly about my browser is being checked and ...
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1answer
331 views

Trying to determine if someone was “DoS'd”

I'm part of a pretty small video game community and one of our members claims he was DoSed or DDoSed during a recent match. We are currently split as some people believe he was and others believe he ...
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3answers
138 views

How to prevent DDoS to cause stored data inconveniences?

Let's assume there are no vulnerabilities in the application layer, one disk, and no physical firewall (just iptables rules in the server itself), hence in this case all the DDoS attack does is to ...
18
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1answer
1k views

Why is the Wikileaks site still accessible? How come it hasn't been hacked? [closed]

Let me get started by saying I think Wikileaks is great, and that their work is invaluable. Background/context for this question: The recent Wikileaks data dump on the CIA. I've visited the site ...
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3answers
270 views

Can a person be non-DDoSable? [closed]

I have a friend who claims he cannot be DDoSed by a conventional web booter. We have tested this with him multiple times. The public IP given to us when he joins a server, I.e. client connection ...
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1answer
449 views

How bad it would be? If hackers managed to take down all 13 Root DNS servers at the same time? [closed]

Would such huge DDoS attack can cause any economical damage? How severe this DDoS attack would be, if all 13 Root DNS servers got successfully DDoSed/flooded and taken out? Would any websites even ...
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1answer
272 views

Are Anti DDoS server farms really effective?

I'm looking to host a web app in a datacenter and I'm considering a few options. All of them seem reputable and claim to offer Anti-DDoS protection. If just about every hosting provider is offering ...
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1answer
851 views

Coding to detect DDOS [closed]

I need to code a program in order to detect a DDOS attack. I'm not sure what's better: 1) use TCPDUMP in order to listen to the interface 2) code my own way to listen to the interface (using C ...
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0answers
2k views

LAN-side UDP Flood [closed]

My internet has been really slow these days, and it takes around 5 minutes after the computer starts to even being able to open a webpage. I've checked my router logs and it says I'm being port ...
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4answers
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How to deal with this denial of service attack on an Apache server?

I was the target of different attacks today. The last one created this traffic on port 80. Apache is down and the load on server remains high. Firewall is enabled. Any suggestions? 15:27:10.203993 ...
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1answer
3k views

What is Ingress filtering and how does it work?

I know that Ingress filtering is used to try and verify that a packet actually came from the ip address that it claims to have come from. But how is it possible to verify this when all you have is the ...
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1answer
149 views

Clean and cheap protection for user registration HTTP requests?

I am developing a website that has user registration. I already built some rate-limit protection techniques using nginx and at a lower level using iptables, but I am worried about real-world attacks ...
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2answers
129 views

Mediawiki/Nginx/Php on Ubuntu 14.04 is being attacked

I had a personal wiki set up with mediawiki on my server with nginx. Recently I noticed that all my sites that used php (Mediawiki and all Wordpress sites) were not responding or timing out. Then I ...
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0answers
228 views

What is the meaning if all IoT hacked by Mirai all over the world identify themselves on my server since 15 days in the rhythm of 180 unique IoT/h?

In the past 15 days 57,000 unique Mirai IoT devices have attempted to connect and it’s constantly growing (180 new IPs/h). 88.9% come one time and never come back. We have checked. It’s Mirai botnet, ...
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1answer
1k views

What happens inside of a DDoS Scrubbing Center?

I understand, that traffic is redirected to a scrubbing center during a DDoS to differentiate between malicious and legitimate traffic as has been explained in this post. However, from a technical ...
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1answer
6k views

Iptables rules to prevent IP Spoofing

We had following below iptables rules that exist in our web front-end boxes to prevent IP Spoofing: -A INPUT -s 255.0.0.0/8 -j LOG --log-prefix "Spoofed source IP" -A INPUT -s 255.0.0.0/8 -j ...
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4answers
12k views

Why does a (D)DoS attack slow down the CPU and crash a server?

So I get the basic idea of (D)DoS used for flooding, but I don't quite understand how this causes servers to crash or get them to slow down due to CPU overuse. As far as I know, the thing that is ...
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4answers
524 views

How do URL shortening services like bitly prevent ddos attacks? [closed]

i am working on a project that needs to shorten URLs to of about ~25 chars of length. I can create cryptic ids which map to full length URL and persist it in a DB. My only worry is how can i prevent ...
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2answers
2k views

DDOS attacks and multi-threading

Does a host create a separate thread for each TCP SYN request? Or it depends on the socket implementation for the host?
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4answers
237 views

DDoS: A protocol where the victim says “Don't send me traffic for N ms”?

When a server senses (whether or not true) it is under DDoS attack, how about a protocol where it sends a non-spoofable message upstream to routers saying "Don't send traffic to my IP address for N ms"...
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1answer
1k views

GRE DDOS — Wouldn't the firewall block it?

So I've been reading up on Mirai. And I found out that it implements a rather unique attack, described here, where it floods the victim with GRE packets. GRE is IP protocol number 47. Now here's ...
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2answers
1k views

remove mirai virus on router

I need some help with removing the mirai worm on my rounter. Few days ago my ISP was on cyberattacks which it have affected over 100,000 customers who couldn't be able to get access to the internet ...
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4answers
7k views

Can I protect my router from a Mirai Worm and how do I know if I'm vulnerable?

Today this article was published by the BBC: Talk Talk and Post Office routers hit by cyber-attack. It states: It involves the use of a modified form of the Mirai worm - a type of malware that is ...
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1answer
231 views

Is the Mirai malware attacks related to the TR-069 is a classic port attack?

Refering to the following topic: http://arstechnica.com/security/2016/11/notorious-iot-botnets-weaponize-new-flaw-found-in-millions-of-home-routers/?utm_content=buffer8f018&utm_medium=social&...
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1answer
119 views

Is a router a better device for a IoT botnet than something in the router's network?

As some of you maybe noticed, there was a attack this weekand against routers of the german provider Telekom an their routers "W723 Typ B" and "W921". According to the news here in Germany, they ...
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1answer
573 views

Does Windows firewall stop attack use bandwidth?

If I block all the international traffic except an IP range and an attacker starts a DDoS attack on my IP, will it effect on my bandwidth?
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1answer
2k views

Host sending massive amount of TCP/IP Packets with RA Flag: Part of DDoS Attack?

I have a host on the Network that tries to send TCP/IP Packets to various servers. The DST Port is always 80 or 443 and the Flags set are RST and ACK. These Packets are blocked by our firewall. I did ...
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1answer
71 views

Security mechanism for quick checkout (without cookies/session id)

I am implementing quick checkout in my e-store. Customer only have to enter email and phone number to make an order, system checks whether customer with such fields already registered, if not it ...
0
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1answer
242 views

How are Distributed Denial Of Service (DDOS) attacks resovled [duplicate]

I just realised that I don't know how (denial) of service attacks are resolved especially in the long term. The attacking machines don't get tired and there must be some cooperation involved in ...
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2answers
2k views

How is the strength of a DDoS attack measured?

The DDoS attack on Dyn by Mirai malware that disrupted the internet was largest of its kind in history. Experts say that its strength was 1.2 Tbps. I don't understand the math behind it. How is the ...
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1answer
96 views

What if IoT devices are fabricated with random passwords?

Considering the Dyn DDOS attack which was possible because the IoT devices have poor default passwords, will it be a solution if the company who produces the devices might generate random default ...
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3answers
697 views

What happens to zombie machines after DDoS attacks?

Do the zombie machines that takes part in a DDoS attack belong to ordinary people just like you and me? Can we be the part of a DDoS attack even without realizing it? What happens to these slave ...
6
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2answers
907 views

Is BCP38 enough to stop DDOS attacks?

BCP38 is a network security standard which has the scope to prevent spoofing the source of DDOS attacks. The main idea is that the ISP shouldn't forward traffic which is not coming from it's network ...
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1answer
250 views

Is it possible to crash the Internet? [duplicate]

Could a skilled hacker given the resources crash the internet itself? With more and more people joining the internet everyday, it would be becoming increasingly easier for hackers to just, overload ...
74
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4answers
12k views

Did I participate in the recent DDoS attacks on Dyn's DNS service?

It was reported that the recent large scale DDoS attack affecting multiple websites in the US was done by hacking 10s of millions of devices and using them for the attack. How can one in general know ...

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