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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DNS Amplification attacks [closed]

For an academic paper,I need to simulate a DNS amplification attack and show how it can be mitigated.How to go around simulating a DDOs attack,because I don't have zombies at my disposal and I don't ...
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5answers
4k views

How do major sites prevent DDoS? [duplicate]

As far as I know, I have never heard of or seen any large scale web sites like Amazon, Microsoft, Apple, Google, or Ebay ever suffer from DDoS. Have you? I have a personal philosophy that the bigger ...
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1answer
47 views

What's the typical approach to caching invalid authentication attempts?

Clients (actually software pieces developed by some random dudes all over the Internet) are authenticating on a web server using "basic" authentication scheme and to do so they are passing the ...
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2answers
209 views

How could a SYN flood affect a home router

I was curious how a DoS attack would affect a home router. In particular, I'm interested in how a SYN flood would affect a home router. The reason I'm interested is due to a Cisco document I read. ...
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1answer
53 views

Downloading operating systems vulnerable to TCP amplification

I am doing a security research project on TCP amplification, and was looking to download vulnerable OS's for testing. From what I have researched mostly ancient linux kernels (2.0.x and below) and ...
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2answers
31 views

unprivileged or privileged malware for botnets

For those malwares which are used to organize botnets to DDOS a website, they just need to send and receive HTTP packets. Do they need to be privileged? If they dont need to be privileged, is it true ...
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2answers
87 views

How web application firewalls protect application from DDoS attacks?

How to protect a web application from DDoS by the implementation of Web Application firewalls? How effective is this method?
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1answer
84 views

Can the attacker launch a sufficiently large SYN flood to overwhelm the victim's server?

Suppose that the victim's web server infrastructure can process 200,000 TCP connection requests per second. Assume that a single connection request (TCP initial SYN) requires 40 bytes to transmit. The ...
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1answer
74 views

distinguish between bots and legitimate clients [closed]

If an attack (DoS & DDoS) involves thousands of bots, how can the server distinguish them from legitimate clients?
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1answer
104 views

defend against LOIC Hive Mind attack

Other than client puzzles, what are some things a website can do to defend itself against a LOIC Hive Mind attack? The Low Orbit Ion Cannon (LOIC) is an attack tool which features a user-friendly GUI ...
2
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0answers
112 views

cisco asa syn flood detection and response not working

I have a Cisco ASA 5510 (ASA Version 8.3(2)) that has been getting a syn flood attack on it (or more accurately through it - targeting a host behind it) a couple of times a day for the past few days. ...
2
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0answers
64 views

Ubuntu server seems compromised for a DDOS attack [duplicate]

So i have this VPS Ubuntu v12.04 Server running with DigitalOcean. Zpanel/Apache/PHP stack was installed on the Server For the past few days it was occasionally down. Initially, I didn't know what ...
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1answer
143 views

How to prevent ddos and brute-force attack by restricting IP's on Wordpress website

I want to make wp-login.php and/or wp-admin accessible only from one country. If I want wp-login.php access only from USA then my approach from .htaccess is like below <Files wp-login.php> ...
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3answers
86 views

Is opening a new mysql connection for each query potentially unsafe?

I am doing some unit testing and noticed that if I click (or have multiple people clicking) the same filter very very fast (very precise I know;) eventually I get a "The connection is already open." ...
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1answer
103 views

Why do I target the proxy server if I send a DDoS attack from it?

I once read that if I send a DDoS attack via a proxy (for example with LOIC), I won't target the server I am trying to send a DDoS attack to but I will actually DDoS the proxy server. Most important ...
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3answers
107 views

Questions about ddosing?

Suppose a website is hit by a 500 Mbps DDos, and then the DDos stops for a second or so; does the website recuperate?
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3answers
156 views

Distributed Denial Of Service Attack Mitigation

Is there any way in which you can stop a DDoS attack(or any measure that you can take), if the packets sent by the attacker look like normal traffic? I got the question on an interview (how would you ...
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1answer
603 views

Strange flood of requests to my web server

About an hour ago, strange requests began showing up in my access logs. They are coming in at a rate of ca. 400 req/s and appear to come from IPs all over the place. It started out at a lover rate and ...
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1answer
66 views

Identifying attacks by network activity

Is it posible (and how) to tell from a network dump if there is a buffer overflow attack, DoS or brute force attack? A DDoS would be more obvious to identify, but those attacks mentioned above I think ...
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31 views

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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3answers
237 views

How to identify if my site is vulnerable to DOS/DDOS attacks? [closed]

I am hosting a site on a hosting server. How to identify whether my site is vulnerable to DOS/DDOS attacks?
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2answers
165 views

Will a DDOS attack prevent outbound traffic?

Imagine a scenario where there is a DDOS attack against a target - clients would be unable to connect to the target, but I would like to know if the target could initiate a connection to the outside, ...
0
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1answer
241 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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1answer
123 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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2answers
122 views

Solution for traffic capturing from router

i'm a newbie and i'm having a problem that i can't find it by google. I'm researching abbout DDoS detecting method now. As we can see that nowadays people often analyze networking traffic from router ...
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1answer
109 views

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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0answers
307 views

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 ...
6
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3answers
2k views

Can someone launch a DOS attack on my IP

Suppose, I have a static IP on my PC and is known to others. None of my softwares listen for remote connection. Is it still possible for someone to DOS attack me in such cases? If yes, how it is ...
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3answers
1k views

NTP DDoS Attack on Home Servers

After some half-good script kiddies found out about this exploit or DDoS method, they have been doing it like crazy to websites, game servers, and now my home servers which allows me to work on some ...
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2answers
206 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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3answers
483 views

Can anyone DDOS my server with jmeter? Do they need a powerful server for that?

Is there a way to DDOS my web app through jMeter? Can anyone DDOS with a simple PC? I couldn't find any answer here. I would appreciate if anyone could help me out.
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2answers
915 views

Blocking incoming traffic from privileged port (< 1024) to mitigate DNS DDos Amplification attacks

Hope someone can clarify. As I understand, in a DNS DDos Amplification attacks Multiple DNS queries are sent to a vulnerable name server with the source IP spoofed to that of the target server. The ...
2
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1answer
385 views

Lots of failed outgoing sshd attempts. Am I hacked?

For the last two days I've been seeing lots of lines in my /var/log/auth.log that look like: sshd[xxxxx]: error: connect_to 0.gravatar.com port 80: failed sshd[xxxxx]: error: connect_to ...
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3answers
723 views

Strange Apache access logs

A site of ours has been targeted by some kind of strange attack and I am trying to work out exactly how it has happening. Basically, the strangest thing is that the logs seem to correspond to entirely ...
2
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2answers
1k views

Outbound DDOS attack from a centos server

We run a mail server (postfix/dovecot/centos 6.4). The hardware is based on a supermicro chasis with IPMI features. It also runs a web interface for accesisng mails(Apache web server ) Recently our ...
2
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0answers
188 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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1answer
109 views

DNS zone size overload?

Is it possible to DOS DNS by creating custom dns zones with lots of text records in them so that the size of the DNS zone is in the order for example 100 Gigabyes, and then query all the dns records ...
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1answer
137 views

What packet parameters should be checked to detect layer-7 DDoS attack?

What packet parameters should be checked to detect layer-7 DDoS attack (http flood, slow http request etc.)? Do window size and packet timeline show enough information to detect attack traffic from ...
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1answer
105 views

Hacking through a firewall [closed]

couldn't you DDOS attack an firewall somehow so that it would shutdown and you could access the computer?
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1answer
1k views

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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3answers
2k views

Why is it so hard to trace origins of DDOS attacks?

According to the July 2009 cyber attacks Wikipedia article, US & South Korean governments suffered a DDOS attack on their websites. However, up till now they have not been able to find any ...
6
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3answers
1k views

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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2answers
411 views

What could be the reason for the high traffic on the local network? [closed]

In our small company we have very high traffic outbound from local network to server which is getting blocked, and slow downs our server respond time. Especially at night. I am not security ...
2
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4answers
1k views

How to detect bots clicking a link?

I own a url shortening service. I want to deliver only legitimate statistics to my clients. There are possible scenarios that a particular user writes a script to automatically open the shortened URL, ...
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3answers
121 views

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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3answers
634 views

Can one use IP-spoofing to anonymize DDOS attacks?

Since it is possible to fake the source-ip of an ip-package, is it also possible to anonymize DDOS-attacks?
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1answer
222 views

How does IP Spoofing increase the upload speed?

I was talking earlier to a script kiddie and claimed that IP spoofing can increase the upload speed in a DDOS attack?! that does not make any sense to me According to him if your server has an upload ...
3
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1answer
300 views

How does a Distributed Denial Of Service Attack work

Let's assume that a hacker has already infected an X number of PCs , each one of them is online. How will he actually perform this attack? Just send ping requests or use his very precious tool to do ...
4
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1answer
897 views

Can you be DDoS'ed even if you are behind a home router with no open ports?

I was wondering if someone can become a victim of a DDoS attack as home user when only his IP is known by the attackers but he is behind a router with no open ports or other known vulnerabilities? ...
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2answers
860 views

How to send GET/POST requests without header and agent information

I want to test our DOS prevention system against http requests that are not have header and agent information. Is there any tool I can do that. I tried siege with this command siege -c 3 -b -H ...