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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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 ...
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1answer
108 views

I am being DDoSed for no reason, how can I protect myself?

I recently experienced an unprovoked DDoS attack with a speed of 8Tbps against my website from over 80k unique IP addresses and I was wondering is there any way to protect myself against these ...
0
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1answer
71 views

Why is a DNS Amplification attack considered a DDoS attack?

My understanding is that a DNS Amplification attack involves sending a DNS resolver a bunch of requests with a spoofed sender address, which is the victim's. The DNS responds to this IP address with a ...
4
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1answer
1k views

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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1answer
4k views

dns reflection attack vs dns amplification attack

Over the past few weeks I have heard discussions about a DNS reflection attack and a DNS amplification attack. Is there truly a difference between the two or are people just using 2 different names ...
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0answers
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What attack-methods for HTTP/L7-Attacks (Reflection and Co.) are you aware of [closed]

I know the following and would like to collect some more methods on how to attack websites and services via misused 3rd-party-applications: Wordpress PingBack/xmlrpc (seen a lot and wildly used) ...
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2answers
47 views

Repeated “Dos Attack” from remote IPs

I've been having some weird issues with a home network, and it seems to me like I have some vulnerability I don't know about. To be honest, though, I'm not a big network/security guy and I kind of ...
128
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10answers
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I got an email threatening to DDOS me if I don't pay a ransom. What should I do?

I received the following email, addressed to me at an email address on my personal domain (for which I run my own mail server on a VPS): FORWARD THIS MAIL TO WHOEVER IS IMPORTANT IN YOUR COMPANY ...
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1answer
87 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
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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 ...
3
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2answers
68 views

Should HSTS header be sent on an error response?

We need to configure our loadbalancer to send the HSTS header and we are debating whether or not to send the header on HTTP 4xx/5xx responses. Our main concern is application layer DDos attacks. We ...
4
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1answer
274 views

Can a Cisco ASA 5505 block this DDoS attack?

Since more than a week ago, my dedicated server (located at ovh.com) has been under TCP SYN (I think) attack. OVH don't care about it but this attack is killing my server with a high CPU load ...
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Explanation for these entries in the Suricata fast.log?

We have installed Suricata on our system. We have the following similar lines in our fast.log. Can anyone explain these lines? 03/17/2016-17:18:52.744707 [**] [1:2200075:1] SURICATA UDPv4 invalid ...
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0answers
39 views

DDoS Solution for request floods [duplicate]

What are the mitigations to protect from ddos? Is using firewall like cloudflare would help or not? My use case is just want to make sure that no one is sending flood of requests i.e. thousands per ...
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1answer
7k views

Am I getting DDOS attacked?

There has been some weird activity with my WiFi router after somebody threatened to DDoS me. I am looking at my WiFi router's activity logs and I don't know what I am looking for. What happens is my ...
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1answer
3k views

Azure Based DDOS Mitigation, Azure Based Firewall?

I'd like to mitigate DDOS attacks, for an Azure vm server (just TCP ports 80 and 443). Azure appears to be a great solution. I can't find any Azure documentation, as to if there is an Azure ...
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0answers
102 views

What is an Origin Error Attack?

Similar to my previous question here, however I thought it was best to ask two separate questions rather than combining them into one. From The Forrester Wave™: DDoS Services Providers, Q3 2015 ...
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2answers
305 views

Sophisticated DDOS attack

According to this article, ProtonMail was the victim of a very sophisticated DDOS attack. "At 2pm there was a dramatic escalation," said Yen. According to Yen and Gargula the attackers smacked 15 ...
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0answers
28 views

SYN Flood from fixed spoof IP but receive only one packet

Why i flood many packet to a victim from 1 fixed IP+Port. But on Victim i netstat see only one SYN_RECV packet
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0answers
61 views

From a topological point of view, are there any network structures which weaken a DDoS attack?

I am aware that I am doing some abstractions here (link-layer-3/link-layer-2 and router topology comparison, for instance). However, I wonder if there are any network structures (so-called ...
1
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2answers
264 views

Where can I get a list of “bad” IP addresses that are likely to be used by attackers or spammers? [closed]

Is there an open source project or a list of "bad" IP addresses or ranges that are likely to be used by attackers or spammers? UPDATE: ideally I want it to be a service call so I can call it using ...
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1answer
72 views

DDoS amplification attacks

I have been learning DDoS atacks and how to be protected from it. But I have a question: What are the common services being misused in UDP amplification DDOS attacks?
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4answers
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Looking for botnet IP address feeds to protect against DDoS

I would like to get a live feed of botnet IP addresses delivered from a service and block them under certain conditions. Preferably community based/open source but open to looking at worthy commercial ...
2
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0answers
56 views

Rogue Containment on a wired network (mostly)

I work as a security analyst for a large company. The answer must provide remote support. We are currently looking to build a piece of software (integrating existing products with home grown ...
2
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1answer
61 views

If a firewall deletes DOS packets before they reach the designated application. Is it then possible to break trough the firewall with a DDOS attack?

My Question is that if a Firewall blocks for example a DOS attack of UDP packets. Is it then possible to "break" or take up the capacity of a server by sending enough packets trough a DDOS attack? or ...
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1answer
46 views

Does using the same mail and web server increase a risk of DDos due to IP exposure?

I use the same server for sending my emails and web hosting. I send user registration and support forum mails from my server and occasional marketing mails or newsletters. I read on a CloudFlare blog ...
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3answers
498 views

TSource Engine Query DDoS attack

My gaming machine is under DDoS attack and when I used Wireshark I found the following string "TSource Engine Query" in all UDP packets coming from random IP's. I found using Google that some gaming ...
10
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3answers
2k views

Is there any way to stop DDOS attacks? [duplicate]

As many other webmaster I am facing problems with DDOS attacks. I have tried denying offending IP addresses from htaccess files and using bigger and better hosting, but I am unable to stop the attacks ...
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1answer
80 views

Dealing with a DDoS: horizontal vs vertical scaling?

I'm reading this paper about DDoS protection in AWS. One of the benefits of EC2 is that depending on the instance, it can scale for minimizing the effect of the attack. In the paper there are two ...
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0answers
95 views

How to keep my VPS server up on Hulk.py attack

This question in not duplicated, I tried everything that was published on stackexchange websites, but could not fix my problem. I have a web server. OS: Ubuntu 15.10 Configured on Apache2 Ram: 1.5 GB ...
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4answers
302 views

How can I remove an unknown device from my wifi network?

I have an OnHub (from Google), and there is a device I don't know on my wifi network. Is there some way for me to kick it, or DDoS it, whether through some command line command on windows or ubuntu, ...
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7answers
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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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1answer
57 views

In house mitigation for a volumetric DDoS attack

Can a volumetric DDoS attack be mitigated by some in house defense or does the defense always need to be on the cloud? If yes, then why?
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2answers
140 views

DDoS Mitigation - Whitelist or Blacklist Incoming SOURCE Ports?

For a network offering webservices, I have had recommendations to blacklist a couple of common incoming DESTINATION ports, such as UDP 53, to combat the increasing load from DDoS. I'm wondering if it ...
2
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0answers
56 views

Securing API against DDoS attacks

I have designed a backend service which is only accessible via a custom REST API. As I understand, services such as CloudFlare are designed to protect HTTPS traffic, and do not apply for custom APIs. ...
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0answers
60 views

Are link-flooding attacks a real threat or only an academic scenario?

I read some papers about link-flooding attacks (i.e. flooding network links) and I wonder if these attacks are really of relevance in the real-world and what makes them so dangerous compared to ...
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2answers
133 views

How hackers implemented DDoS attack with 602 Gbps?

Everybody's heard about DDoS attack with 602Gbps Bandwidth that crashed BBC site, But is really Botnets and hacked servers can implements an attack in this scale ?
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2answers
82 views

Preventing a web-page from getting hit from another server

A DDoS attack may result from a website attempting to access the resource of another website. For instance, example.com (attacker) is trying to access resources on example.net (victim). The ...
31
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2answers
877 views

Digging into DDoS attacks (includes hostile IP's from multiple honeypots)

I have been tracing a series of DDoS attempts, and am wondering if anyone else has seen anything like them. I've downloaded the following Powershell script which scrapes Terminal Server (RDP) Event ...
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120 views

Wordpress pingback attack

I am getting Wordpress pingback attach on my server. I tried to put if condition on nginx to block deny all requests that contains "Wordpress" in the header. It works fine but still nginx get millions ...
0
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3answers
189 views

Why does an overload of requests give one root access all of a sudden?

There's this saying that using a DDOS-attack, people first attack a server using millions of concurrent requests and by doing that they miraculously gain access to the server. How does this work? Why ...
4
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1answer
136 views

How can CloudFlare save your website if the attacker knows the IP of the server?

I saw CloudFlare's services where you need to change the DNS of your domain name to their provided DNS address. The traffic coming as "mywebsite.com" goes through CloudFlare. What if I have a ...
37
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11answers
33k 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 ...
4
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6answers
1k 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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4answers
3k 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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5answers
335 views

DDOS Server Attacks & Domain Names

I'm currently with a web hosting account whose servers seem to be constantly down due to DDOS attacks. I check my analytics daily and I'm seeing a major surge in fake traffic for several of my URLs ...
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0answers
77 views

CPU load of iptables to deny IPs during DDoS event [closed]

If a server has an external IP address protected with an iptables whitelist rule to reject all by default except from 3 ip addresses ip1, ip2 and ip3. If someone identifies this external IP address, ...
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48 views

How to find which domain in my VPS triggered a DDoS attack with WP xmlrpc

Today, my data center suspended my VPS for DDoS attack reasons. They say one of my clients, that has WordPress website, started a DDOS attack to another websites using xmlrpc. But I don't know which ...
11
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2answers
178 views

What is a Poison Dart attack?

From The Forrester Wave™: DDoS Services Providers, Q3 2015 report, (emphasis mine): Attack types defended CGI request, denial of capability, diluted low rate degrading, direct, DNS ...
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1answer
102 views

What's the best way to block all external proxy IP's which could be used for pivot points or as a DDOS Source?

At the simplest form - the question is to block external proxy due to an emergency situation due to which management have forced technical teams to get a solution to block all the external proxy or ...