I have linux firewall configured. I want to check the stress tecting on this firewall. is there any way to launch attack of DDOS or other attack which try to make the firewall busy ?
View 2 Replieshow can I track a Dos and DDoS attack on a server . Does linux have any goiod known command line utilities and log files to us e in this way?
View 1 Replies View Relatedi have 1 question no more because i got many ddos attack and my load is 95++ what is the best program to stop DDOS Attack ?
View 14 Replies View RelatedI have a server and i think that my server is under Ddos attack. i see that server is not having much load and only few process runs but my site opens very slow. i executed the following command on my ssh:
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Is there a way to check older iptable rules that were loaded? I accidentally overwrote my iptables and that has killed internet access to all computers in the intranet. I must have accidentally deleted some line in the iptable rules and cannot figure how to get it back to how it was. I am using Debian 5.05 by the way.
View 1 Replies View RelatedIn my new Centos i am not able to add iptable rule. iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128bash: iptables: command not foundI am getting this error. I use this rule to forward ports to squid.
View 5 Replies View RelatedI went away from home for a few days, ... Now I am back at home and noticed, that my server is going out with 100% available bandwidth. The server is mainly Http / Ftp / Mail server, so I stopped all services, to see which one it is. ervices stopped, still 100Mbps go out like ants in the flood.
I updated the system, made a backup, installed IPtraf. It seems that I have something 'installed' and my server is running something to attack User computers. It seems to try to find something on random IP's random ports. I am a little bit confused now. As long as my sites are running, I'm ~OK~ but sooner or later I would like to have my bandwidth back. How could I try to hunt down which service/app/process got hacked?
It seems that the monetary system of our society got now more enemy's than friends. Capitalism seems to reach it's end. But my server is serving also ART! Sooner or later we will need to pay copyright even for our thoughts. I was reading today, that the French president wants to punish file sharing as his wife made 3 albums, and wants to get some money ..
Attack Sneaks Rootkits Into Linux Kernel Quote: A researcher at Black Hat Europe this week will demonstrate a more stealthy way to hack Linux
Apr 14, 2009 | 04:21 PM
By Kelly Jackson Higgins
DarkReading
Kernel rootkits are tough enough to detect, but a researcher this week has demonstrated an even sneakier method of hacking Linux. The attack attack exploits an oft-forgotten function in Linux versions 2.4 and above in order to quietly insert a rootkit into the operating system kernel as a way to hide malware processes, hijack system calls, and open remote backdoors into the machine, for instance. At Black Hat Europe this week in Amsterdam, Anthony Lineberry, senior software engineer for Flexilis, will demonstrate how to hack the Linux kernel by exploiting the driver interface to physically addressable memory in Linux, called /dev/mem.
"One of bonuses of this [approach] is that most kernel module rootkits make a lot noise when they are inserting [the code]. This one is directly manipulating" the memory, so it's less noticeable, he says. The /dev/mem "device" can be opened like a file, and you can read and write to it like a text file, Lineberry says. It's normally used for debugging the kernel, for instance.
Lineberry has developed a proof-of-concept attack that reads and writes to kernel memory as well as stores code inside the kernel, and he plans to release a framework at Black Hat that lets you use /dev/mem to "implement rootkit-like behaviors," he says. The idea of abusing /dev/mem to hack the Linux kernel is not really new, he says. "People have known what you can do with these /dev/mem devices, but I have never seen any rootkits with dev/mem before," he says.
Quote: "The problem with kernel-based rootkits is that the rootkit can mitigate [detection] because it has control," he says. "It's a race in the kernel to see who's going to see who first." [URL]
I have full hdd encryption with a rather long key. The thing is the FBI might just show up at my house one day and have a warrant for my PC, and who wants the government looken through there life? I have a few plans on geting my PC shut down before they can get there hands on it. This is all well and good, but if they can sniff my key from the ram It doesn't matter what my key is or weather they find the computer on or off. Anyhow, i was wondering if there was some way I could add a script to the shut-down process that would over-write the ram.
View 11 Replies View RelatedMy server and clients (NFS and NIS) are in continuous attack via ssh. Somebody is trying to guess password and login, and making port 22 busy.What are different ways to stop this attack?I am thinking to block this ip in iptable but I have no good idea because I have not done this before. Any special consideration do I have to take while doing this thing? How is it done and which file does it modify?
View 14 Replies View RelatedI have been receiving attack alerts. And I would like to root out the source of the problem. I'll give you the messages. If you could help me prevent this hacker from even being able to attempt these things please any advice is helpful. There have been memory stack attempts, failed sys_admin conversion attempts, password file write attempts etc.....
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I don't know if FC15 has the iptable rules like the ones shown below by default or not but I wanted a second opinion about the safety they provide. Why is icmp accepted (INPUT rule 1) from/to all ip? and is it better to remove this rule? When the protocol is all (INPUT rule 2), does it mean from ip layer and above?? and is it required/safe to have this rule? The 3rd rule is to allow tcp-port 22 connections (ssh) to/from all ip. I think this is correctly set and required. The 4th rule in INPUT table rejects pings with the icmp-host-prohibited message; which I don't think is the best solution. Instead it can be set to silently drop icmp packets. Then, the FORWARD table uses reject instead of silent drop for forwarding icmp ping packets.
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what do you think about the new rules and their order?
I've got the latest version of Flash installed,and it works most of the time,t occasionally a video or game will stop working and the area it was in will just turn into a grey box. Usually it only does this if I leave the page the video's on, but it keeps doing it when I'm playing Robot Unicorn Attack on Adult Swim's site, too
View 14 Replies View RelatedI was just wondering if you were to get DDoSed/Dosed would ubuntu block the packets or protect you in some way?
View 1 Replies View Relatedmy computer froze solid, and it would not react to anything. X didn't react to Ctrl+Alt+Backspace, not Ctrl+Alt+Del, so I had to turn it off using the power button.
This is the first time my computer freezes like this, the log files did not reveal any HW errors. Is it possible that someone in the channel did not like my level of Java skill, and flooded me to disconnect?
By the way; Im using slackware 13.1 with the default kernel (2.6.33.4) and irssi as IRC client.
I know that if you eg. ICMP-flood someone, the traffic will be denied and, but can it provoke other behavior from the computer?
So my question is; can a IRC flood/DDoS attack cause a computer to freeze sub zero?
recently my Apache server crashes very often; by watching the error log,I've notice several signs of intrusion.So, I think the problem can be a denial of service attack against my machine.My distribution is Debian Lenny.
View 2 Replies View RelatedI have about 5 machines that are under Ddos daily and I use rate-limit for Iptables to protect that and it works good.My UDP ports 20100 to 20400 are actually under Ddos so these are the commands I use:
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A INPUT -p udp -m udp --dport 20100:20500 -m state --state NEW -m recent --set --name DEFAULT --rsource
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Well someone has been putting up this attack on my game-server ports. For those of you who don't know what type of attack this is, so its an attack which is actually masked to us because the attacker uses his machine to send packets to a machine called source which reflects the packets to destination. Based on this, the UDP port under Flood at the destination starts making outgoing connections to that IP and gets rejected which uses up more than 5mb/second bandwidth instantly.
I've worked out on some security for this and now need a tool to test this against my machine. I've used PentBox but that's not really powerful to do anything. As I search Google, I find something called Trinoo but can't download or test it.
I have configured a DNS server on my RHEL 5.0 machine.
I have just come across a term Denial-of-Service attack (DoS attack) or Distributed Denial-of-service attack (DDoS attack).
how can I prevent my DNS server from DoS attacks.
Last day i have faced an attack on Apache/2.2.14 (Ubuntu).A user shoots 53 hits within 20 seconds from same IP and as a result db connections to MySQL increased.
a.) Is there any way in Apache to block these type of requests
b.) how can we trace when this type of attack happened to Apache.
Also I have noticed an entry in Apache error log during attack period
Error Log
[Wed Jul 20 20:28:49 2011] [debug] proxy_util.c(1806): proxy: grabbed scoreboard slot 0 in child 753 for worker http://localhost:8294/
[Wed Jul 20 20:28:49 2011] [debug] proxy_util.c(1825): proxy: worker http://localhost:8294/ already initialized
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I want to implement blackhole attack in ns-2 using the aodv protocol. I dont know how implement and i dont have code(c and tcl)
View 1 Replies View RelatedI want to test syn flood attack in my pc
but i dnt know how to generate it, can you tell me
how to generate syn flood attack in pc
I have just configured Centos 5.5 LocalMailServer with fetchmail and sendmail , Proxy with Squid and FileServer with samba. Now my concern is security.. How can i protect my server with outside attack. Will I need to block some ports or I need special tools or script so no one from outside can attack my machine. My machine is working on intranet with local ip only.. No web server or static ip exists. Machine is connected with ADSL router to access internet.
View 5 Replies View RelatedQuote:
The 605-page PDF document reads like a listing of the pros and cons for a huge array of defensive and counterintelligence approaches and technologies that an entity might adopt in defending its networks. Of particular interest to me was the section on deception technologies, which discusses the use of honeynet technology to learn more about attackers� methods, as well as the potential legal and privacy aspects of using honeynets. Another section delves into the challenges of attributing the true origin(s) of a computer network attack.
I have implemented two machines one for honeypot(192.168.100.10) and another(192.168.100.20) to remotely log the honeypot log file using syslog. Inside honeypot I emulated another 3 machines with services on virtual IPs of that same block.Now honeypot is working and I can see the logs generating as I did a portscan(nmap) on those virtual IPs from .20 machine.All of the machines are running ubuntu.
But does anyone know any s/w or tools which originally attackers use so that I can get a clear picture of what happens from the logs. Having problems creating these attack scenarios.
Explain the following iptable rules for me?
I understand 1 and 2, 1 creates the new syn_flood chain and 2 redirects all SYN requests to the new syn_flood chain.
I'm having trouble understanding 3 and 4. can someone explain to me in laymen terms the --limit 1/s and --limit-burst 3?
I would like to ask something. Today my network Internet access suddenly slowed down, after inspecting the problem the hard way we disconnected one of our servers(ip=190, debian squeeze) from network and the network was alright again. When we plugged it back in, following symptoms were observed: computer 190 pinged gateway app. each 6th time. gateway(debian lenny) pinged computer 190 app each 6th time whole network Internet access was slowed down, local network functioned just fine
While pinging themselves, i ran iptraf on icmp packets on gateway and I saw what i thought was ping attack, lots of echo request coming from external address to computer 190. Blocking that address in iptables didn't help but restarting the gateway did, network Internet conenction is at full speed and gateway and computer 190 ping just fine.
My question is, what steps should I undertake in similar case (it's second time in 2 months) - to debug similar problems. Is it even possible for ping DOS to this kind of damage?
I may not be a code worrior, yet I have been a Ubuntu convert from Apple for about 3yrs now. Since 1984-2006 now hackers or viruses. And Until now Ubuntu has been clean, well I have been good with repos, etc.
1. Recently I found "Odd" behavior with my Amarok 1.4 player, ffmpeg, winff.
2. During a Synaptic upgrade there were some "unauthorized changes". I have seen this before due to some of my software, so I ignored it. . .
To my bewilderment, "It" erased Amarok 1.4 player, ffmpeg, winff, all image kernels, claimed domain over my system permissions, and external HD. B4 I shutdown, downloaded LUCID 10.4. . . restarted, then copied over all info possible to minimize a complete delete of my system. Upon restart, indeed all kernel images were gone, Only live CD allowed me access to repartition my HD.
NOW. I have Lucid running, and have been denied access to my external HD and partitioned (internal HD). I used Nautilus to copy over files to my internal laptop HD, yet permissions continue to be an issue. The INFECTED FOLDERS are owned by "User 999-user#999. I must micro manage every folder and file to gain "partial permission". The dialog box stutters and never allows me to go down to "Root"
I have a LAMP server that has been up for a month or so before I get stuff like this:
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60.12.233.54 - - [24/Jul/2010:22:46:07 -0400] "GET /w00tw00t.at.blackhats.romanian.anti-sec:) HTTP/1.1" 404 895 "-" "ZmEu"
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Using Opera 10.61 and 10.62, I find that any secure website I access, such as a bank, the lock icon in the address bar is replaced by a question mark. Clicking on it brings up a window, stating that the connection is not secure, that the server does not support TLS Renegotiation. Doing some internet searches for "opera tls renegotiation" brought me to a page at the Opera website, where they discuss this issue. The issue is generic, not limited to Opera, affecting the TLS protocol, and it potentially enables a man-in-the-middle to renegotiate a "secure" connection between a server and client, issuing own commands to the server. Opera has addressed the problem on the client end, but now servers need to be upgraded too. None of the HTTPS sites I have tried have upgraded their servers, if the information provided by the Opera browser is correct.
My questions: how feasible is such a MITM attack, what level of resources would such an attack require? What, if anything, would the attacker need to know about the client and/or server to mount the attack? Would I be better off using Firefox, or is Firefox simply oblivious of the problem and not issuing warnings for that reason?