A denial-of-service (DoS) attack is an attempt to deny service to legitimate users by sending extreme amounts of requests to a server.

learn more… | top users | synonyms (1)

1
vote
0answers
73 views

How do I stop a simple DDOS attack? [migrated]

There is a hacker who is mad at us, and has started a DDOS attack against us. I think he is a script-kiddie, using tools like DarkComet; the attack is probably simple. I host a server on my PC. The ...
0
votes
2answers
45 views

Questions Regarding DoS

I have a few questions i still haven`t been able to get an answer to. If someone DoS you, do it affect all computers connected to the router or just the computer that is being attacked? For example: ...
-1
votes
1answer
51 views

How does Cloudflare's DDOS protection work? [closed]

I am interested this purely because no matter how many times I read up on DDoS protection, I never really understand how it works. The nature of DDoS is that botnets will flood your server with HTTP ...
1
vote
1answer
31 views

Webserver accessible only from CloudFlare?

I wan't to avoid getting DDoSed as much as possible i can, so i thought if it's possible to set my web server to communicate only through CloudFlare. Any request from another source will be rejected, ...
0
votes
3answers
30 views

How ping a server which has ICMP blocked

I'm trying to ping a server which has ICMP blocked with normal ping. It's showing: Request timed out Is there any other method to ping it?
1
vote
0answers
49 views

How to get around a DDoS fully? [closed]

my network is currently down from a DDoS attack and I need to get around it. So far I found by switching to Googles DNS servers, I can access only some sites but not all of them. Is there another way ...
7
votes
1answer
762 views

What is a safe ping frequency without it being considered a DDoS attack?

I am trying to chart the uptime of a server by regularly pinging it and Google and then comparing the ping times. I want to keep doing this over a period of—let’s say—a week. I am sending a set of 5 ...
2
votes
1answer
96 views

My home IP (supposedly) was involved in a DDoS attack

There did not seem to be any SO community dedicated to computer security, so I'll ask here... As the title implies, my home IP (supposedly) was involved in a DDoS attack. I got a phone call from a ...
0
votes
2answers
160 views

Is it possible that I have caused a DoS to my son's tablets

I have three Internet connections at home, they are not connected to each other in any possible way, they are from three different ISPs FTTC #1 , the white modem and the black and white router ...
0
votes
1answer
57 views

Is this a DDoS attack?

I need some help identifying whether or not this is a DDoS or just a random network issue: Not really sure what to do...should I complain to my host? Change the IP?
9
votes
3answers
2k views

Will the maximum speed of a network card reduce the impact of an incoming DDoS attack?

I’m wondering if the maximum speed of a network card would reduce the chances of a DDoS affecting a home-hosted website. In this scenario, I’m hosting my website from an Android Tablet where the ...
0
votes
1answer
72 views

DDoS/botnet or what's going on, cloudflare.com?

This is small output from tcpdump -i re1 'port 25': 14:00:10.732034 IP cf-190-93-254-113.cloudflare.com.http > MY_IP.smtp: S 4234708404:4234708404(0) win 8192 <mss 1412,nop,wscale ...
0
votes
1answer
159 views

DDOS on port 443?

Recently my friend asked me whether his network is secure because he is setting up a game server on port XXX. I opened up Nmap on my linux machine and found port 443 opened. I tried to access ...
0
votes
0answers
181 views

Configure Router for better DDoS protection Actiontec MI424WR

So for the past month, my server has been attacked by script-kiddies three times. The server is mainly used as a minecraft server. I am getting worried that this is becoming an outbreak as many of ...
1
vote
0answers
28 views

How can I efficiently filter Dos packets? [duplicate]

I have recently been the victim of some Dos attacks. The facts : I received a very high amount of packets saturating my connection and preventing me from accessing the Internet during one hour ...
0
votes
1answer
277 views

Compromised Debian server sending DDOS attack

I have a server online that apparently has been compromised and it sends DDOS attacks to another ip. The system is a debian 7 server, hosting a few wordpress, joomla websites, and airtime to host a ...
-2
votes
1answer
72 views

Protected from attacks through Skype

I know that people can find your IP through Skype and try to DDOS it and take your Internet down for a couple of minutes or hours. What I would like to know is: How many people need to DDOS you at ...
0
votes
0answers
649 views

Linux message: Possible SYN flooding on port 25. Sending cookies

I have a Linux CentOS server online. At my console this message appeared: possible possible SYN flooding on port 25. Sending cookies. See SYN flood and SYN cookies. I have done an Apache JMeter ...
0
votes
1answer
156 views

Block Google Docs from retrieving file on website - Stop Google DDOS [closed]

I was reading a very interesting article on how someone used Google Docs to preform a DDOS attack on a website. They basically filled a Google Docs Sheet with =image() requests to download a certain ...
2
votes
0answers
97 views

How to mitigate IP fragmentation attacks before reassembly when authentication information is available?

I'm trying to filter incoming traffic to high bandwidth, low latency network, to mitigate DDOS. The incoming traffic is custom UDP (I'm setting the protocol specs so I can force IP headers if ...
1
vote
0answers
44 views

A lot of random NAT tables appear

My brothers Mac seems to be infected. It keeps on sending UDP and SYN floods to our router, and it multiplies my ping 10 times.When I look in the NAT Mapping table there are a lot of random address ...
1
vote
0answers
117 views

Block packets by size in Windows

currently I am receiving an attack against one of my services running on Windows Server 2008 R2 with malicious UDP packets all of a specific length. I have tried dropping these packets with a plugin ...
0
votes
1answer
97 views

Can Torrent/DHT network remember my IP?

I suspect that my torrent activity casted some sort of "natural" DDOS attack on me. I had UPnP configured and each time I was starting uTorrent client, it was generating new random port and was ...
0
votes
1answer
437 views

Measure DDOS attack strength

I have been puzzled on this theory. Assume Server B is sending DDOS attack to Server A, so is it possible for a random client A, to be able to measure the attack strength, like the client A was able ...
1
vote
2answers
152 views

Can a home user behind a firewall be targetted by a DDoS attack?

I've read about an attack that targets simple home computer users who are playing online poker: Players A and B join a real money 1 on 1 tournament. You cannot unregister from this tournament and if ...
1
vote
1answer
138 views

Remove Windows 8 Nag (which executable to delete?) [duplicate]

I'm currently experiencing a Windows 8 DoS. When this nag ribbon is open, I cannot use the machine: I've tried closing the ribbon with ESC, ALT+F4, and a few others that used to close programs. I ...
0
votes
1answer
1k views

Is /root/b26 a DDoS process?

I have found this process: /root/b26 Here is a top: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 20810 root 20 0 339m 808 360 S 100 0.0 27:39.95 b26 I have ...
0
votes
3answers
86 views

Can I authenticate multiple times to one access point?

I'm attempting to test the security and stability of a new wireless access controller and assigned, it a has a /24 subnet of IP addresses to use for giving clients DHCP. I'm wondering if its possible ...
0
votes
2answers
2k views

DDoS attack on SMTP

I am not sure whether this is the right place to ask this. But now I am in a great difficult situation. Our server is undergoing SMTP DDoS attack. The mail service has been totally down. We have ...
1
vote
2answers
169 views

Why is preventing DDoS so hard? [closed]

I was thinking, if a DDoS attack can come in 2 ways: Sending large packets. Sending many packets. Why don't network administrators limit IP connections, to let's say 3 users/IP's and set a limit ...
-4
votes
2answers
302 views

VPS hosting and DDoS attacks prevention

I'm curious if there is any way to create such a network so that if one machine is hosting a couple of VM's and one of the VM's gets attacked, it doesn't take down the network. Is there anyway to do ...
-1
votes
1answer
156 views

If someone downloaded 600GB , can that be a DOS attack

Last night someone exploited some vulnerability in my site and then upload a PHP script to my images folder. I have an Amazon EC2 server with CentOS. Then the hacker downloaded 600GB and increased ...
2
votes
1answer
153 views

What this command :(){ :|: & };: does? [duplicate]

What does this shell command do in Linux :(){ :|: & };: How can it be used in Denial of Service attacks?
1
vote
1answer
2k views

Wireless router lods reporting loads of DoS attack attempts

We're having intermittent connectivity issues with our ADSL at the office. We've been dealing with our ISP for weeks and they don't know how to fix our problem. What happens is that at multiple times ...
4
votes
1answer
827 views

Was this a DDoS, a hack attempt, or something else?

I SSH’d into my home server earlier because it was taking strangely long to respond to HTTP requests. I noticed that the shell prompt was also acting slow. So I typed top, and saw several instances of ...
0
votes
1answer
931 views

Logging incoming IP addresses on a specific port

I've tried tcpflow and iptables but I'm unable to do so. I believe someone is attempting to DDOS my open port which is a server, so that my clients are unable to connect. From tcpflow I'm able to get ...
0
votes
1answer
139 views

Better configuring my firewall for Minecraft

Not long ago I purchased a new server, and I'm planning on running a Minecraft server on it. Now I'm trying to better configure my firewall to stop DDoS attacks on my server while running the ...
1
vote
1answer
317 views

DDOSED, Static IP but ISP says dynamic

I'm having a problem, sometime I'm getting ddosed for no reason (I verified with commview,wireshark). The first time I noticed I didn't think it was a problem because I was pretty sure my ip was ...
0
votes
1answer
262 views

How do I drop the entire INPUT chain from iptables?

On Linux, I've been building a malicious IP list. I assume the DDOS is now gone. How do I drop the entire INPUT chain from iptables, without affecting the FORWARD or OUTPUT chains?
-5
votes
1answer
6k views

How to solve DDOS attacks in Windows Server 2008 R2 / Windows Server 2012? [closed]

Any software for windows Writing custom (intelligent) microsoft windows firewall extension (C#/C++/C) Writing custom (intelligent) firewall for windows Installing nginx etc. on the same computer and ...
0
votes
1answer
273 views

MacBook Air gets added to Watchguard XTM-21W Appliance's Blocked Site List?

We have this issue where one of our MacBook Air (Mountain Lion) users is periodically getting added to the Blocked Sites list within our Watchguard XTM-21 Appliance (XTM21-W). Couple of questions: ...
2
votes
2answers
316 views

Can an attacker create a DoS attack by sending TCP data segments?

I know about DoS by TCP SYN segments & want to know can it possile a DoS attack by TCP data segments?
1
vote
3answers
366 views

GoDaddy is attacked by Anonymous. Any way to bypass the DDoS to access email? [closed]

GoDaddy is attacked by Anonymous. Any way to bypass the DDoS to access email? We have all our email hosted and need access to it to operate.
1
vote
1answer
453 views

Route gameserver traffic through cloudflare? [closed]

I use cloudflare for my website and we have a gameserver I was wondering if it is possible to route traffic through cloudflare. This recently sprung into my head when I realized that I could route ...
-1
votes
1answer
154 views

My server got a DDos attack; how can I debug further from logs? [closed]

My server got a 13 GBit DDoS attack so LeaseWeb nulled its IP address and the attack ended. My IP address is still blocked. I got a temporary second IP address, which is not yet public. How can I ...
0
votes
2answers
1k views

CSF/LFD - would I really need CPHulk enabled also?

So if I have the default configuration of CSF/LFD firewall running, should I enable CPHulk, or does CSF/LFD already do what CPHulk does? If the answer is "No, CSF/LFD does not do what CPHulk does", ...
2
votes
0answers
542 views

How to get rid of DOS attack: RST Scan?

I have Netgear Wnr1000v2 router. I have set my NAT to secure mode ( I don't know if that helps ). Many a times when I see my router's log I see lots of DOS attack: RST Scan. I somehow think that these ...
1
vote
3answers
897 views

How to force Apache to answer only to Cloudflare?

I'm sure you all know what Cloudflare is (it's a very famous CDN). What I want to do, is force my Apache HTTP server to ONLY answer to Cloudflare. I want Apache to ignore and close or not respond to ...
2
votes
1answer
266 views

Is it a DOS or DDOS if the attacking computers are on the same network

I'm currently doing a reflective report (reviewing someone else's work) for uni and the report is about DDOS. For the report the author carried out a DOS attack on a web server using computers that ...
14
votes
1answer
584 views

How come sites like Google/Facebook/etc. don't get DDOS'd even though they receive so many requests?

Something I don't understand: (Tens/hundreds of?) thousands of people simultaneously try to connect to a site like facebook.com or google.com. From what I understand, they must all necessarily ...