we have a server that is being attacked by a piece of software along the lines of "port****".
Basically it sends a lot of requests to a single port to kill it, this port being port 80 (http) and killing web interfaces.
Its being used to take a website off line.
What is the best way to defend this? And the quickest way, we have access to the server, its running Fedora.
1- I have 2 servers attacked in same time.
2- The public interface experiences a high packet loss. There is a heavy inbound attack to the public interface which gets maxed out at 100MB.
3-There is no target outlets ports
4- I have changed apache port and the DDOS still attack my server
softlayer servers (Washington, DC)
can any one tell me what's the reason of this problem ?
and how to fix it even though there is no port exposed?
softlayer servers (Washington, DC)
my server is being brute force attacked at port 22.. It caused my server to be blocked by my ISP's upstream...
at first I follow the instruction on this forum showthread.php?t=456571 (can't post link)
but then I realized (from the upstream email, I don't have access to any log on their side) that it was UDP.. not TCP.. but it was said to be brute force attack on SSH port.
Now all I do is moved ssh port.. and then limit the max connection per minute to port 22/UDP like on the above tutorial page..
Is that enough? I can't use IPTables to permit specific IPs, I'm pretty much very mobile so my own IP is different each time.
Any ideas why UDP attack?
Is it possible that brute force attack turned out to be UDP protocol? cause if it's not, then I think my ISP/its upstream can't be trusted..
I'm runnung a server with Apache2 (Apache/2.2.16 (Debian 6.0))
I would like Apache2 listen on port 8080 for IPv4 and on port 80 for IPv6.
This is what I have now:
/etc/apache2/ports.conf
Currently I am using Linux + cPAnel and using the port 25 for email sevrer. Currently we facing 1 problem is, some user's ISP is not support port. May I know how can I add additional port into server and allow users to send mail by different port?
View 1 Replies View RelatedI have an office internal website and I opened a port in the gateway of my office (7080) to this website (server )'s 80 port. That makes this website open to public as office has static IP. And then when I view the site from home . it's fine. But when I tried to login, the site is using a pop-up, I guess it's http authentciation, login, I was redirected to a url without my port number any more, that stops my access to the site as obviously I would.
How can I keep my connection/port number ...?
about the NIC and switch,
there are giga port vs mega port,
in your experience,do they really be different?
I recently changed my SSH port, but locked myself out when my APF firewall was installed.
Where would I got to add a custom port inside the APF's config file?
Quote:
Mar 10 20:17:55 host kernel: printk: 102 messages suppressed.
Mar 10 20:17:56 host kernel: printk: 3 messages suppressed.
Mar 10 20:18:01 host kernel: printk: 98 messages suppressed.
Mar 10 20:18:35 host kernel: printk: 34 messages suppressed.
Mar 10 20:18:51 host kernel: printk: 189 messages suppressed.
Mar 10 20:18:56 host kernel: printk: 195 messages suppressed.
Mar 10 20:19:02 host kernel: printk: 249 messages suppressed.
Mar 10 20:19:06 host kernel: printk: 36 messages suppressed.
Mar 10 20:19:21 host kernel: printk: 3 messages suppressed.
Mar 10 20:19:26 host kernel: printk: 342 messages suppressed.
Mar 10 20:19:31 host kernel: printk: 509 messages suppressed.
Mar 10 20:19:47 host kernel: printk: 54 messages suppressed.
Mar 10 20:19:51 host kernel: printk: 421 messages suppressed.
Mar 10 20:19:56 host kernel: printk: 542 messages suppressed.
Mar 10 20:20:01 host kernel: printk: 785 messages suppressed.
Mar 10 20:20:16 host kernel: printk: 340 messages suppressed.
Mar 10 20:20:21 host kernel: printk: 337 messages suppressed.
Mar 10 20:20:26 host kernel: printk: 430 messages suppressed.
Or is this something else? It's been going on for about 40 minutes. I seen my load jump to 20, to 100 and back and fourth
I'm sure that i have Trojans and Viruses on my Server but every time i contacted My Company they ask me to pay money and then they will check and scan my server
so is it any Free application which can scan and remove all bad files on my Server? i'm looking for free applications to scan the whole server
My server stop responding, I couldn't access via webmin or ssh, and DNS were not responding, so I have to ask for a reboot and now everything is fine.
Looking at the logs I found this:
Code:
Jul 18 19:23:12 server sshd[18484]: Failed password for root from 61.145.196.117 port 56817 ssh2
Jul 18 19:23:12 server sshd[18485]: Failed password for root from 61.145.196.117 port 60227 ssh2
Jul 18 19:23:13 server sshd[18488]: Failed password for root from 61.145.196.117 port 38038 ssh2
Jul 18 19:23:15 server sshd[18493]: Failed password for root from 61.145.196.117 port 49884 ssh2
Jul 18 19:24:30 server sshd[18497]: Failed password for root from 61.145.196.117 port 37929 ssh2
Jul 18 19:25:06 server sshd[18521]: Did not receive identification string from 61.145.196.117
Jul 18 19:25:09 server sshd[18508]: Did not receive identification string from 61.145.196.117
Jul 18 19:25:14 server sshd[18505]: fatal: Timeout before authentication for UNKNOWN
Jul 18 19:26:00 server sshd[18509]: Did not receive identification string from 61.145.196.117
And searching that IP on google I found it here: http://www.tcc.edu.tw/netbase/net/in...?fun=240&prd=3
And is flagged as a SSH Attack.
Any ideas why my server stopped working? and how to prevent it?
Im using CentOS 5.0
i found my site load slowly, the cpu load is good. I run this command
[root@host ~]# netstat -nap |grep SYN |wc -l
526
It's seem my server is having problem with SYN attack. Is there anyway to protect it ?
I'm running apache 2.
My site currently in prolong HTTP flood attack since 2 weeks ago. The attack was never stop and for this moment i could only mitigate the attack using my own firewall (hardware).
Since my ISP is not interested to help from upstream, even provide any mitigation services, i could only doing mitigation on my own source or using proxy services alternatively as well, but i've chose to tried on my own. I've tried once on one of well-known mitigation services out there but it seems not fully satisfied me since most of legitimate traffic is blocked from their source.
What i could do now is keep staying alive as well as will not going down on whatever situation becomes worst (but if the attack change to udp attack, i couldn't help myself coz there must be high incoming bandwidth into my network). My network is totaling 10MB last time but since this attack i've been forced to subscribe for 30MB in order to keep balance on the attack.
I've blocked all access except for my country and some other neighbours. If i change policy to allow all countries, the load of firewall will become max and after that hang will hang in less than a minute. I've done load balancing of 4 servers (8GB memory each one) and it seems the condition is getting under control with slight problem of server hang (memory shortage) and very limited keep alive connection.
Now what am i thinking is to buy a router objectively to null route incoming specific IP of countries so i can change my firewall policy to allow all connections as well as to help the firewall itself release its burden halting blocked IP that currently keep hitting itself that could might impact its performance.
Which brands of router is possible doing this thing?
Do you have some other suggestions instead of buying router?
i am just having one issue in one of my highly visited website hangibar.com, its being hosted in softlayer, we are facing synattack too much in this website.
the solution which microsoft given in their website related with tcp/ip registry entry but thing is same , some where and some connections become increases too much over tcp/ip. due to that reason website become very sticky and it stop functioning the execution of sql process, during this issue i have to restart the server to establish a fresh connection.
im getting a syn attack and my vps getting overloaded what im doing is banning ip's that gets most connections
after banning server get normal but if there anyway to stop this post method
My server is under dos attack (http) , I have installed APF firewall and ddos deflate. I configure them to work together.
now if any IP with more than 100 connections is black listed by dos deflate, I can see it in apf's deny_hosts.rules file.
everything seems correct, but my server still very slow.
the ip which is causing that has more than 1000 request and is blacklisted.
There are lot of perl process with 100% usage on server. When i tried to view error_log it shows following:
[root@local ~]# tail -f /var/log/httpd/error_log
=> `Lnx.txt'
Resolving gihkus.com... 208.98.48.116
Connecting to gihkus.com|208.98.48.116|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 16,577 (16K) [text/plain]
0K .......... ...... 100% 316.78 KB/s
05:26:03 (316.78 KB/s) - `Lnx.txt' saved [16577/16577]
When i tried to view this http://gihkus.com/Lnx.txt it seems to be attack on my server. http://gihkus.com/Lnx.txt is not hosted by us. I have disabled perl support on all domains hosted on our server but still we are under attack. There is nothing special in /tmp.
Over the past day one of my servers has seen a huge rise in incomming traffic (from normal web requests to a constant 4Mbit/s, peaking upto 80Mbit/s). My outgoing traffic has remained at its normal profile, so I am pretty sure that these are not web requests, and it does not seem to be having an adverse effect on the server (the site still runs perfectly well and quick and load is still less than 1).
However, I am unsure as to how to identify what this traffic is? Are there any easy ways to tell on a FreeBSD server what the source and type of incomming traffic is? I have tried playing with netstat, but an not getting anything useful - I would like to see which ports are involved.
Am Really suffering here for ddos attack ( apache - pop3 ) every week my server under attack am using APF but now am really wanna get red from it am looking for a powerfull firewall I do not know if CSF Could stop this attack like limiting receiving SYN from an ip or any other policy another thing . i have get this rules from forums but am really weak at iptables rules so can any one help my if these rules useful or not . against Dos attack:
iptables -t nat -N syn-flood
iptables -t nat -A syn-flood -m limit --limit 12/s --limit-burst 24 -j RETURN
iptables -t nat -A syn-flood -j DROP
iptables -t nat -A PREROUTING -i eth0 -d (dest ip) -p tcp --syn -j syn-flood
My server is using too many httpd process..I think iam under DDOs attack..I executed the following command..
netstat -an | grep :80 | sort
and the result is this
tcp 0 1491 ::ffff:95.211.10.169:80 ::ffff:213.215.100.110:2263 LAST_ACK
tcp 0 1493 ::ffff:95.211.10.169:80 ::ffff:85.207.126.231:52694 LAST_ACK
tcp ....
I have a windows server, and today it has a large inbound traffic, so I tried to disable all web service, and after that, the result of netstat -an shows no connection at all, but the server still has large inbound traffic,
Do you have any idea about this?
What should I do now?
Our server is in attack since 4 days. Http port busy all the time.
When I type :
netstat -na | grep ":80" | awk '{print $5}' | cut -d. -f1-4 | cut -d: -f1 | sort -n| uniq -c | sort -n | tail -5
It shows :
[root@ ~]# netstat -na | grep ":80" | awk '{print $5}' | cut -d. -f1-4 | cut
-d: -f1 | sort -n| uniq -c | sort -n | tail -5
2 65.19.130.24
2 83.149.120.9
4 204.15.73.243
35 222.254.103.142
5128
[root@ ~]#
I wonder the hidden IP of 5128 ??? How to know it?
The server getting slow with high I/O diskwait then normal, although load is not high.
here is the output of: netstat -anp |grep 'tcp|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n .................
i had installed anti ddos or firewall,but those are useless.His attacks are such great that The server and all the vps are down now. One told me that I should check the ips and receive ips. The attacker is so skillful .describe the best method to defeat him. Be sides the attacker use diffirenet ips in each attack,I block him by iptables but no use…. His attack occupy all the ram and I have to resetart the server… Now this time his attack lead to shutting all the vps down
View 10 Replies View RelatedMy website is under ddos attack from some competitors. I don't know yet how big is the attack. The ips of the ddos attack come from all the world.
I have contacted a few hosting companies specialised in ddos proof hosting, unfortunatly the price is so expensive that i cannot afford it.
So i try to find another solution : my website is only aimed to the french people, so maybe is it possible to install a kind of firewall or proxy located before the server to block all the incoming IP adress not from france ? Do you know some websites who can do this and the price ?
I already try do deny the non-french ip in one htaccess file but the ddos attack saturate the server anyway.
We are currently experiencing an SYN Flood attack on our primary production server and are looking for some help in resolving the issue.
Running:
Novell SUSE Linux Enterprise Server 10.2-64
SuperMicro X7DBR-E Intel Xeon QuadCore DualProc SATA [2Proc]
Processor Intel Xeon-Clovertown 5320L-QuadCore [1.86GHz]
8GB Memory
@ Softlayer DC in Texas.
Need help within the next hour or two. Please ask any necessary follow up questions and how you might go about resolving the issue (i.e. SYN Cookies, etc.)
someone decided to attack my webserver and I can't figure out how to block it.
tcp 0 0 localhost:80 207.44.129.88:2138 SYN_RECV
tcp 0 0 localhost:80 207.44.129.88:2243 SYN_RECV
tcp 0 0 localhost:80 213.66.121.211:63372 SYN_RECV
It's literally thousands of those requests overloading apache. The server is fine, the load average is like .8. But none of the website are loading.
We're hosting with ThePlanet, and they're doing a great job at blocking a huge portion of the attack. But we're still getting hit pretty hard. I've got APF installed, and 3 or 4 anti-dos scripts.
Every once in a while a page will load for the websites, I think we've got just under 50 legit connections.
My server is currently underattack, I have been able to keep it up but after I ban 500 IPs, I get a lot of different IPs again.
Any idea or suggestion to do mass-ban to those attacking IPs?
tcp 0 0 xxx.xx.xxx.xxx:80 190.87.128.59:3965 SYN_RECV
tcp 0 0 xxx.xx.xxx.xxx:80 82.115.52.10:2323 SYN_RECV
tcp 0 0 xxx.xx.xxx.xxx:80 90.148.137.56:21094 SYN_RECV
tcp 0 0 xxx.xx.xxx.xxx:80 189.237.35.155:57605 ...
i,m under attack i got in csf today this
77.195.42.235 # lfd: (PERMBLOCK) 77.195.42.235 has had more than 4 temp blocks in the last 86400 secs - Wed Apr 1 09:39:35 2009
151.60.86.210 # lfd: (PERMBLOCK) 151.60.86.210 has had more than 4 temp blocks in the last 86400 secs - Wed Apr 1 09:39:51 2009
and these two ips was attack me them down site for 2 minutes but then block in csf
so i just wanna ask now this option in CSF
LF_PERMBLOCK : 1
i make it open 1 so this the reason can block the ips attack. or this the reason make them can attack ?
so i should keep this option 1 or make it 0 to stop this kind of ddos attacking?
Our forum is under attack...and our host won't do anything except tell us that our load is too high and that they might turn off our account.
But, we've already turned off the forum...the only load is a note that says it's down for maintenance...no database...no html...nothing.
In a very short amount of time it has has over 300,000 page requests for the same three pages.
Is there anything on my side (since I don't run the server) that I can do to stop this or prevent it...etc?
my exim is under ddos:
exim (pid 8042 8158 8169 8175 8249 8254 8267 8276 8384 8397 8398 8556 8560 8561 8587 8663 8669 8705 8707 8711 8752 8783 8790 8796 8799 8811 8881 8883 8884 8929 8932 8934 9014 9019 9025 9035 9060 9087 9089 ...............)
how can i solve it?
