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

learn more… | top users | synonyms

4
votes
1answer
173 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
votes
11answers
34k 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
votes
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 ...
1
vote
4answers
4k 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?
1
vote
5answers
370 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 ...
2
votes
0answers
78 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, ...
1
vote
0answers
56 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 ...
12
votes
2answers
182 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 ...
3
votes
1answer
105 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 ...
2
votes
1answer
128 views

What is the role of IP spoofing in DDoS attacks?

I've read that IP spoofing is often used in denial of service attacks, and I've also just recently read about ingress filtering, which attempts to use blacklisting to filter out spoofed IP addresses ...
2
votes
1answer
249 views

Mitigating DDOS in P2P systems

In P2P systems where performance and response times are critical individual clients are susceptible to DDOS by publicly exposing their IPs. While there are various mitigation solutions available at ...
3
votes
1answer
169 views

DDoS Attack Protection

Recently I've been threatened with an IP Address DDoS attack. I was wondering in what ways and how could I stop this attack. I'd really like to be able to do this without my parents finding out.
1
vote
1answer
139 views

Must an attacker using a Smurf attack be on the same network as the victim?

I'm learning about Smurf Attacks. Since they need to use a broadcast address, doesn't that mean they can't work over the internet? For example if an attacker sends a router the packet with the ...
3
votes
4answers
2k 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 ...
0
votes
1answer
834 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 ...
0
votes
0answers
850 views

What are the most popular DNS amplification attack tools for Windows and Linux?

I would like to test my edge-router firewall rules against some DNS amplification attack traffic. I could run some DNS lookup utility in an endless loop, but maybe there are some dedicated utilities ...
1
vote
2answers
72 views

How can perpertrators of denial of service attacks, determine the impact their attack has had?

Although I know how a user could mitigate Dos attacks and detect their presence e.g. checking packets received and sent, comparing current CPU usage to normal, comparing network usage to normal etc. ...
4
votes
2answers
119 views

How do DoS attacks work on non-servers?

I understand how DoS/DDoS attacks work on servers. If I have not been misled, it is possible to DoS/DDoS a system that does not act as a server, but is still connected to the internet. How is this ...
3
votes
1answer
167 views

Common attacks when no ports are open

If you have a web server with all ports closed (except, of course, the necessary HTTP) what kind of attacks can an attacker use to hack into the system? Are the only vulnerabilities stuff like ...
1
vote
2answers
142 views

What danger can come from D-DoS over VPN

Every time I use VPN, I get a message to notify me to be sure that my PC is 'healthy' from pots infections. Also I've read in this article to stay away from that. My question, what damage could ...
0
votes
1answer
45 views

Additional Protection Against DDoS

We have subscribed to an upstream ISP's protection service to protect against DDoS. I am thinking of developing a incident procedure in case my ISP's DDoS mitigation fails (highly unlikely right?). ...
1
vote
2answers
94 views

Infected employee using office VPN was part of a DDoS attack

Recently, our office VPN was taken down by our ISP after discovering a DDoS attack. Apparently an employee connected to our VPN is infected. There were no logs at the time of the event. Besides ...
0
votes
0answers
138 views

Deny IP spoof from on ASA destination

on Cisco ASA I am seeing lost of logs like following (127.108.61.90) to 190.93.249.93 on interface inside (127.30.171.61) to 190.93.249.93 on interface inside (127.105.54.108) to 190.93.248.93 on ...
1
vote
2answers
401 views

How can someone DDoS me?

If I've not opened the port 80, how can someone DDoS me? Is there a method or is it possible? Someone said that it's possible, but I'm not so sure, that's why I'm asking here.
3
votes
3answers
1k views

TCP versus UDP resilience to DDoS

I am building a service that I can implement equally well with either TCP or UDP. If I use TCP, I expose vulnerability to SYN flood and other attacks on TCP protocol. If I use UDP, it will be harder ...
1
vote
0answers
33 views

iptable ip_conntrack_max testing

I was trying to understand how ip_conntrack_max works so i have created two VM and set ip_conntrack_max to 10000 I used hping to open 10000 udp connection on VM using following command hping --udp -...
6
votes
1answer
370 views

Is a ddos attack that makes ssh auth attempts a possible way for attackers to significantly impact your system?

I'm noticing on my digital ocean server, that I'm getting a high volume of auth attempts. I don't have any passwords since I use sshe key auth, so I'm not worried about a break in. But can a ...
13
votes
1answer
302 views

Siri DDoS over FM Radio

A few days ago I was driving home and suddenly Siri started to talk by herself in reply to a command I never gave. As you can imagine I have the "hey siri..." feature active, so I can make calls ...
1
vote
3answers
253 views

How to Stop DDoS Attacks by simple function on web server?

I have an overview ideas of the preventing ddos attacks, in a simple way. Please clarify me, if my thinking is wrong. Option 1 From the basic understanding of the DDOS attacks is that the attacker ...
0
votes
0answers
33 views

Options to protect an outbound initiated connection IP?

Consider a service that has 3 separate organizations in a SaaS model. The end user(#1) connects to the first provider(#2) and then initiates a function from within the #2 that connects directly to #3....
3
votes
1answer
676 views

Is it possible to force client use TCP instead UDP for DNS queries?

Assume I am managing a firewall between DNS server and clients. Is there any way to force clients use TCP rather than UDP, so we can prevent DNS spoof types of DDoS attacks?
1
vote
2answers
168 views

Protecting server from bogus HTTP Requests

What would be the recommended approach to block those typical bogus HTTP requests that the server gets bombarded with? Also has this attack/nuisance been named yet or is it generalized as Bot Activity?...
1
vote
0answers
76 views

Ubuntu server seems compromised for a DDOS attack [duplicate]

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 ...
2
votes
2answers
1k views

Am I allowed to DDoS my own server?

I have bought a server and used it to host some game servers or my website. Now I am visiting a computer security course and I would like to test some of the presented attacks. Am I allowed to, for ...
2
votes
2answers
217 views

2 External IPs to prevent DDoS?

In my home network I currently have a Hitron cgnm-2250 acting as a modem/router combo with an IP Passthrough option enabled for a 2nd router connected to it (ddwrt nighthawk x6 r8000). I already have ...
0
votes
0answers
45 views

Behaviour of DNS query packet

When the configured name server resolver is not reachable, the query packet will retransmitted after certain t times (in windows, every 1 seconds until 8 seconds,max). The behaviour of the legitimate ...
1
vote
2answers
87 views

Website Visited by Unresolved Ip

My Website is flooded with unknown visiters Awstats says that my website getting thousands of hits in few seconds. I am using robots.txt and .htaccess, but the problem stays there. Please help me ...
1
vote
1answer
126 views

kernel: Intrusion disconnecting me

I've read about it a little but I'm concerned. It never happened before and for last 5 hours my router gets kernel: Intrusion alerts similar to these: As soon as the kernel: Intrusion is detected, ...
4
votes
2answers
259 views

DDoS attack - where are packets dropped?

I'm researching into ddos attacks to get a better understanding. I've read lots from this community however one thing I couldn't get my head around is packet dropping. So lets say I've identified an ...
3
votes
4answers
3k views

How to mitigate SSL based DDoS attacks?

as you probably know the problem with SSL based DDoS attacks is, that the traffic cannot be analysed and filtered by a DDoS mitigation service provider such as Prolexic, Akamai, Radware, etc. without ...
5
votes
3answers
4k views

My server is used for DDoS attacks

I have webserver (centos + cpanel), and one of the clients used my server for DDoS-ing, how can I identify that client/user? What logs should I look to, is there any settings I can modify so such ...
6
votes
6answers
9k views

Why can't we 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 Nameserver(victim)...
1
vote
5answers
88 views

Does services provided by different companies for DDoS protection work well?

Is it necessary to use any DDoS service provided by different web hosting provider and other people? We know, they are running their business to provide security to thousands of web property. They are ...
12
votes
5answers
7k views

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 ...
1
vote
3answers
997 views

How does blacklisting an IP using a firewall protect against DDoS attacks?

I just read that to protecting a server against a DDoS attack involves blacklisting IP addresses. What does the term blacklisting mean? What does it mean for a firewall to drop a connection? How ...
1
vote
1answer
121 views

Different types of DDoS attacks [closed]

What is behavior of UDP flood, TCP SYN flood, Ping of Death and Smurf attack?
1
vote
0answers
106 views

VPN protection against DDoS [closed]

I am thinking of getting a VON, for DDoS protection and other various things, though what if an attacker knows my real IP already?
26
votes
5answers
3k views

DDOS - security or operational risk?

The chief security officer of a medium sized IT company (400-500 employees) recently released a bulletin in which he stated that DDOS attacks are not a security risk but an operational one. Also I was ...
0
votes
1answer
185 views

DDoS attacks targeting Android

I am currently studying some Android topics and I've been having difficulties finding answers regarding DDoS attacks. My question is: Are Android devices vulnerable to DDoS attacks or does Android ...
1
vote
0answers
17 views

Probabilistic packet marking content ID field

For Above image: All routers are using PPM. What will be the content ID field if 1) R1 = mark packet, R2= Mark packet, R3 = Not mark the packet. 2) R1 = Not mark packet, R2= Mark packet, R3 = Not ...