Security :: Track DDoS Attack On A Server?
Jan 25, 2011how 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 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 RepliesI 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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i 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 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 Replies View RelatedLast 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 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 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 ..
my 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 RelatedWell 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.
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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.
I 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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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 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 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"
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?
mpg123 suddenly started playing a police siren occationly. I checked the process once I heard it, and root was the process owner. How could this happen? Have someone broke into my computer? If so - how could I verify an attack? I run Ubuntu 9.10.
View 2 Replies View RelatedThis is an excerpt from the Linux man page for mktemp command: "mktemp is provided to allow shell scripts to safely use temporary files. Traditionally, many shell scripts take the name of the program with the PID as a suffix and use that as a temporary filename. This kind of naming scheme is predictable and the race condition. It creates is easy for an attacker to win. A safer, though still inferior approach is to make a temporary directory using the same naming scheme. While this does allow one to guarantee that a temporary file will not be subverted, it still allows a simple denial of service attack. For these reasons it is suggested that mktemp be used instead."
- How can a denial-of-service attack be carried out if a directory name is known?
- Why is it important to use mktemp to generate a sufficiently random file/directory name for temporary files?
I got alarm on Firestarter showing attack from samba service on port 139 . Is that ok for my host computer ? or a serious attack .
View 9 Replies View RelatedI'm not concerned about this since this traffic is generated from the loopback address, but would like to find out what it is.
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In my Open-Suse server I have a script, where makepasswd output(by default it generates similar passwords: cGyTbqpr, tpJ1LA, 33EXdo) is redirected to mkpasswd(which uses DES by default) in order to generate salted hash of this previously generated password. I would like to test the strength of this system. I have a quad core CPU, and if I start John The Ripper like this(I want to use -incremental:all flag):
john -incremental:all passwd
..only one core is utilized at 100%. Is there a possibility to make all four cores to crack this password? Or is this possible only after reprogramming John The Ripper? Or what is the algorithm for generating passwords with with -incremental:all flag? I mean if John generates passwords randomly in brute-force mode, then it's smart to start four different John processes simultaneously because then one of those four will find the password firs
What do you use to track security incidents? open source software that does this?
View 8 Replies View RelatedI have joined a number of websites over time and it seems harder to manage them. Would like advice on how to generate passwords and to store and keep track of them. I would like to hear of systems or programs that are good for this.
View 5 Replies View Relatedi need to do a statefull firewall actually i try the ESTABLISHED state but as we know that some people can play with the TCP header so i want to do a "connection track" state, they told me in mangle but i didn't find can someone paste for me a link about "connection track" or write for me rule for ex: to make connection track for port 80!
View 4 Replies View RelatedI am trying to find a best tool to track configuration files changes. I did find some information about osec and mactime, but, it seems, that they are not included in fedora/rpmfusion package databases. is there any tool that can be installed as a package?
View 8 Replies View RelatedContext: I happened to read through an old presentation today on OpenBSD's cryptography page called "A Future-Adaptable Password Scheme". In spite of its age, it still seems relevant and useful. One of the topics it discusses is the problem of "offline" attacks, where an attacker is not slowed down by any system (or other external) security. It's attacker vs. the computational cost of guessing passwords in such a scenario.
Specific question: On several unix-like systems (including Linux), the salt helps make building rainbow tables computationally expensive. It's not enough to guess a password and hash it; the proper salt must be provided as well, or the password will not be discovered.
However, the salt (or the hashed salt) seems to be visible in /etc/shadow. For example:
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foouser:$6$U9a6HdUY$U3qFDMen0wDmL0x5WHm2OWhOgzOZ4MCQxV/oY.i5RhfXCQrLifIVkBpWOd1CbCGimVCjmfxZAaud/sXDf1.mv0:14733:0:99999:7::: So in an offline attack, a rainbow table could be built using precisely that salt, correct? (Yes, I realize /etc/shadow is not readable by non-root users, but I am considering an offline attack.) Building the salt (or the hashed salt) into the hashed password seems to defeat the purpose of using a salt altogether.
My 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?
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I ran across the above article, which described a DoS attack in which requests are sent very slowly to the Web server. I'm running lighttpd 1.4.28 on a Gentoo Linux server, and I'm wondering if there is anything I could do in preparation to defend against such an attack.
A bug report [url] seems to indicate that there was a patch in place already against this sort of attack, but I wanted to be sure that was the same thing and if there was anything else I needed to do.