Denial of Service is a family of attacks that attempt to force a target to use up resources (CPU time, memory, bandwidth etc) through flood a target with useless packets, connections or tasks

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What is DDOS TCP KILL?

I've recently been introduced to Kali Linux's webkiller tool, located in the websploit category. It works on the concept of Tcpkill. I don't understand how the DoS attack with Tcpkill works. Can ...
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How can I protect my “try it with one click” service?

I have a service with "try it now" experience that currently offers a "one click" effort. This service has a pool of N resources (lets say 50). Each new resource takes about 1 hour to generate. ...
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do ISPs implement security measures?

For example, if a user is receiving a denial of service attack, with huge amounts of packets being sent to him to disrupt his service, will the ISP notice and stop the offending traffic? Another ...
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DOS attack to increase packets received from a single request?

Is there any attack out there that can be implemented where a single request to a server i host for example responds by sending the same file say 20 times back ? the idea behind the attack is to DOS ...
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2answers
117 views

Preventing a Computational DoS Attack in Public Key Cryptosystems

I'm designing a server which accepts anonymous messages using ECIES: as in, anonymous users send the server an ephemeral EC public key, and the server uses ECDH to derive a shared secret, and some KDF ...
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Does clicking lead to DoS attack? [closed]

I have a website. Suppose someone will code a program that will click continuously on the links of my webpage: could this lead to a DoS attack ?
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483 views

API Key DDOS prevention method

Hi I just wanted some feedback on a DDOS preventing php script that I'm designing. It quite simple and I wanted some feedback on whether you guys think it would be effective. I'm currently using the ...
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399 views

what type of attack does LOIC do? [closed]

I have used LOIC (Low Orbit Ion Cannon) earlier . Today i was reading on wikipedia that there are many types of dos attacks , namely SYN attacks , HTTP flooding ,UDP flooding ,etc and two questions ...
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How to prevent Cookie-Bombs?

Egor Homakov made a nice writeup (Cookie Bomb or let's break the Internet) on how to crash CDNs and other websites with cookies. Although this is a user/browser-side DOS, I'm wondering how one would ...
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373 views

How can I test a DoS attack against snort?

I need to set up an scenario where an attacker DoS attacks port 80 of an server while snort and others users try to connect to port 80 at the same time. Something like this: 1000 connections to port ...
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181 views

Wordpress: Thousand of mail sent to my site from an unknown user! Site is near to be blacklisted by Google

Recently an employee of mine developed a website in WordPress. Things were all fine until we received an email from Google , notifying me that some stuff that can really create security issues is ...
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how to block ip from head or ping or get or post to webserver (using apache and windows)?

am using apache 2.4.9 latest with windows 7 i am using some modules like limitipconn_module security2_module but using wireshark i get unlimited request to busy my webserver (DOS) from some ip ...
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What type of attacks will a SMTP server face if it does not have ratelimiting while sending mails?

Assume a web site with some kind of mailer option, that doesn't implement any rate limiting: This enables users to send an unlimited amount of email per second. Will SMTP face possible DoS attacks ...
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Best way to report a foreigner attacker's ip to authorities?

I have been under attack last week and I was able to trace down the attacker and get his IP address. The attacker was located in Germany but I live out of Europe? From your experience what is the ...
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Active Directory - Denial-of-Service [duplicate]

How can I prevent a user on the domain from launching a denial-of-service attack against Active Directory by scripting bad password attempts against every user in the domain?
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335 views

OWA + AD Lockout Policy: Quite the Mixture

Many organizations have webmail exposed to the world. These sites are often hooked up to AD for user authentication. Are there any specific security controls OWA (Outlook web app) has that would ...
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3answers
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Security considerations in concurrent applications

I have been building a network application with a Client/Server model, where a central server handles multiple client threads. I did my best to ensure that no matter what context the program is run ...
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904 views

Are my Snort rules correct?

I am trying to do a Snort demo and I though it would be nice to detect a real threat. I picked the sasser worm and the jolt/teardrop dos attacks for the demo; no particular reason. Out of the three ...
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How To Protect Tomcat 7 Against Slowloris Attack

I'm using Apache Tomcat 7 to run my webapp on Linux. I scanned it by Acunetix and it's telling me that my webapp is vulnerable to "Slow HTTP Denial of Service Attack". How can I protect it? Acunetix ...
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Root/Naked domain and DDOS

Some services like Github has DDOS mitigation measures for their root/naked domain, but not other subdomain(s). What so special about the root domain concerning the DDOS attacks? [1] ...
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Akamai or Incapsula (or other) for CDN with DDoS Protection? [closed]

One of our clients is launching a new site and I've been tasked with making a short overview of the advantages/disadvantages of Akamai, Incapsula or other CDN providers who are strong with DDoS ...
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418 views

How to avoid DDOS against Kerberos Authentication Server

I have a school project where i am supposed to implement a Kerberos based infrastructure (AS, TGS and resource server). It is already done and working, but i started thinking about how to protect the ...
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Harden a server against mass SSH DoS attacks

How can a Linux server be protected against an attacker that tries to open a large number of SSH sessions (probably trying to brute force a password) that no ports remain to be able to legitimately ...
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Using pattern matching to make a port more secure

I am planning to make a web application deployed on a port more secure by detecting the pattern of the request an then comparing it with the patern next time that IP tries to connect.Any ways to move ...
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327 views

DoS stress test not working [closed]

First off I'd like to say this is my first post on StackExchange, so please let me know if there's anything wrong with it. Also, I don't know much about networking and I'm just making a simple java ...
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226 views

How to force “expensive calculation” when clients connect to my server?

Page 183 of Secrets & Lies on countering denial-of-service attacks: Some researchers have proposed defenses that force the client to perform an expensive calculation to make a connection. ...
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DOS safe alternative to delay response to an attacker with sleep()?

tl;dr sleep() costs my servers resources. Using it to delay response to the attacker might cost him/her time, but allows for DOS. Is it possible to keep him/her waiting without costs of mine? Long ...
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Can someone help? I'm getting Dossed!

So basically since a few days my internet started being very slow. I checked my router logs and guess what! In the log where it is a record of DoS attacks it showed something like |Description ...
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3answers
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What are some good ways to prevent a malicious visitor from maxing out our customer's API maximum allowed service calls?

We run an API service. We gave our customer a package for max limit of 12000 API calls / day. He reported to us that a user has been on purposely visiting his web page 12,000 times a day in order to ...
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How to prevent DHCP Starvation attack?

All this while, I assumed that switchport security is enough to prevent DHCP dos attack. If I set it maximum 1, there can be no more mac addresses packets. But, a friend told me that using the tool, ...
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Why would you want to initiate a DoS attack on a system you are testing?

What is the value of a DoS attack as part of a security assessment? this is the question asked to me in EC council's exam preparation, so need to know. not intending any attack
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Ping Of Death reconstruction against a Windows 95 virtual machine

For the sake of demonstration, I'm trying to perform a Ping Of Death sent from a Kali Linux virtual machine to a Windows 95 virtual machine (vmware) on a private network. I've set both vms correctly, ...
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First steps in preventing DOS attacks

My server is currently being attacked from another server. This is my log: root@my-server:/var/log# tail -f auth.log Feb 19 11:53:08 my-server sshd[3745]: Disconnecting: Too many authentication ...
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RESTful API URLs and Denial Of Service attacks

I overheard the following statement today: We shouldn't use /api (e.g. in a RESTful URL like /api/v1/users/get) in our RESTful URLs anymore because it makes it easier for people to Denial Of ...
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Zlib DEFLATE decompression bomb

Can you give me an example of a short data string that, when decompressed using Zlib's DEFLATE method, expands to something much much longer? More precisely: what is the nastiest decompression bomb ...
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527 views

Snort not showing dropped/blocked packets

This question is about SNORT- I m basically trying to detect PING FLOOD attack. I have included the rule**(drop icmp any any -> any any (itype:8; threshold, track by_src, count 20, ...
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Tools for performing HTTP FLOOD attack?

I'm looking for tools which can perform HTTP FLOOD ATTACK . I seached a lot and this is the only tool I've found DoSHTTP. Does anyone know another tool? I want to test them on my localhost to find ...
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To what extend can a DOS attack succeed even if it was detected?

While reading DOS detection and prevention http://staffweb.cms.gre.ac.uk/~lg47/publications/LoukasOke-DoSSurveyComputerJournal.pdf I've asked myself: Even if a firewall detects a DOS attack and begins ...
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How to patch against RefRef's DOS attack

Overview Anonomous claimed responsibility today for the Denial of Service attack against wikileaks. They are using a new software called RefRef. It seems to exploit MySQL using the server's ...
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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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Packet size and flood attacks

Do the attackers use small but a lot packets or big and some? e.g. 2 bytes or 512bytes? Also , can packet size affect the size/speed of the attack? Something more , how do the firewalls block dos ...
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How do DoS/DDoS work?

In the last days one could frequently read about attacks from anonymous and LulzSec against different platforms like Sony or HBGary etc. Yesterday for example they DDoS'ed soca.gov.uk and jhw.gov.cn. ...
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How dangerous is it to allow arbitrary webhook urls to post to?

I am building a Ruby on Rails API that posts to webhooks that the API user can create, whenever a resource that he manages is created, updated or destroyed, using the HTTParty gem. This got me ...
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TCP Peer unexpectedly shrunk window messages in dmesg log

We get quite few messages like these in our dmesg log on various servers: TCP: Peer 0000:0000:0000:0000:0000:ffff:d431:5861:56369/80 unexpectedly shrunk window 2522304441:2522312601 (repaired) TCP: ...
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How is DDoS different from DRDoS?

I understand DDoS is a DoS assault from multiple sources, where a coordinated stream of requests is launched against a target. How is DRDoS different?
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Security implications of adding all domains to CORS (i.e. Access-Control-Allow-Origin: *) [duplicate]

I am curious of what all the security implications are if I set the following two HTTP response CORS headers; Access-Control-Allow-Origin: * Access-Control-Allow-Credentials: false The only ...
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How can I stop this attack on my router?

After enabling system log on my Asus DSL-N10E router, I've got this message: DoS: Tcp SYN With Data Attack source=217.74.166.73 What does it mean? Is it a real danger on my network security? And ...
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What types of hacking attacks happen alongside a DOS or DDOS attack? [closed]

I'm trying to find some good material on this topic for a paper I'm trying to write for class. Any and all help is very much appreciated.
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What are HTTP GET/POST flood attacks?

I want to know what the main differences are between HTTP GET and POST flood attacks and mitigation strategies for both. I searched a lot but I really can't find some good articles nor examples about ...
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Possible DOS Attack? And solutions for it?

I don't know whether it's appropriate to post this question here but I desperately need help. I've been receiving ping requests from 18 different IP addresses so far. Some of them are local, some ...