Security :: Is Server Under DdOS Attack - Not Having Much Load And Only Few Process Runs But Site Opens Very Slow
Aug 5, 2010
I 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:
I installed for the sheer pleasure of it a webserver. includes apache2, postfix mail server, MySQL, MyDNS nameserver, PureFTPd, SpamAssassin, ClamAV, etc etc. (I have tried to use the config panels ispconfig and webmin)
The situation: There are 3 sites listed on the server, All 3 on different virtual hosts (obviously). The http access goes trough the 20080 port since my ISP blocks everything below 1024 (the bastards). I use a linksys router (192.168.1.1) with dmz pointing to 192.168.1.100 (server) The sites on the server:
inphone.be fraksken.be fraksken.is-a-geek.org (but appearently not geek enough) I also gave them own IP's: 192.168.1.95 192.168.1.96 192.168.1.100
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.
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.
I 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 ..
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
If a site reaches a point where 1 machine simply isn't enough to handle it, what exactly is done? I've heard of "round robin DNS load balancing", but that's obviously not going to work if the site has CGI scripts/a substantial backend of any kind as that data will have to be copied over to every server, and I'd guess that that's not feasible. If the site uses a MYSQL server, and a second web server to take over the extra traffic from the first is put up (how would traffic be redirected to it?), when it makes a database query, it still has to connect to the 1st server, so, we're not really solving the problem at all, it remains just the same. So - how is it done, for large, high traffic sites? (possibly like LQ itself?)
Slow access to web site using squid and Internet explorer.I am trying to troubleshoot an issue I am stuck on. We have a website that is loading .htm documents extremely slow when using Internet Explorer 8 behind Squid. When we bypass the proxy and go directly out to the internet all is fast and pages load fine.But when the proxy is on documents will take sometimes up to 6 minutes to load.This issue is only apparent using Internet explorer 8.I do not see the issue when using firefox with Squid.I have tried to use the no_cache directive thinking it may have been the cache but that didn't work either.I am attaching our access.log, store.log and squid.conf.
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 (188.8.131.52) 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.
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 am having a web server (apache) and 3 sites are hosted in it, named as www.web1.com,www.web2.com and www.web3.com. I need to restrict www.web2.com to Internet users and allow only to local network. At same time I need to allow www.web1.com and www.web3.com to both Internet and LAN users.
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.
There are around 173 zombie process on my client's server, my question is whether zombie process on the server will make server's load unstable like it goes to 20-26 suddenly and comes down and goes high suddenly,will zombie process consume system's resource?..
recently i setup new LAMP server , after some days faced a strange problem? suddenly the server load goes to 100 or 80 but there is no wearied process running? the normal lod is between 0.5 to 1.5? the server have 2 hdd on hardware raid 0
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:
Code: A INPUT -p udp -m udp --dport 20100:20500 -m state --state NEW -m recent --set --name DEFAULT --rsource
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.
I 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.....
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.
This 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?