0
votes
3answers
228 views

How to protect server from simple DoS attack

Please note I am NOT asking how to protect server from DDoS. What I mean is that if someone runs siege -c 1000 www.example.com on his VPS. That will result in my server serving thousands of requests ...
8
votes
2answers
1k views

Linux: prevent outgoing TCP flood

I run several hundred webservers behind loadbalancers, hosting many different sites with a plethora of applications (of which I have no control). About once every month, one of the sites gets hacked ...
5
votes
4answers
1k views

How to stop a ICMP attack?

We are under a heavy icmp flood attack. Tcpdump shows the result below. Altough we have blocked ICMP with iptables tcpdump still prints icmp packets. I've also attached iptables configuration and ...
-2
votes
4answers
372 views

Getting attacked, what do I do? [duplicate]

Possible Duplicate: My server's been hacked EMERGENCY I'm getting millions of these requests in my Apache access log. How do I stop them? 173.59.227.11 - - [30/May/2012:18:23:45 -0400] ...
3
votes
1answer
165 views

Buffer-stuffing denial-of-service attack

I started seeing this odd sort of effect that resembles denial-of-service attack against a Linux server. The effect is that the network becomes at least partially unusable very much the same as what ...
2
votes
2answers
187 views

How do I locate a process on Debian Linux that is creating a large amount of network traffic? [duplicate]

Possible Duplicate: My server's been hacked EMERGENCY We have a remote Linux (Debian) server, which is, apparently, being used as a platform to commit a DoS attack. We have been warned ...
3
votes
2answers
774 views

iptables rate-limit module problem

I am using iptables' rate-limit module to prevent DoS attack (I know it cannot stop a full scale DDoS but at least it can help with smaller attacks). In my rules I have something like: ...
1
vote
3answers
476 views

Fail2ban advice on banning IP's and HTTP

I've recently installed fail2ban as a way of keeping one of our web servers secure from SSH attacks and HTTP attacks. At the moment I'm getting a lot of ssh attacks but fail2ban are banning and then ...
0
votes
2answers
203 views

CentOS Server keeps grinding to a halt, then comes back up

CentOS 5.2 LAMP server The server slows down to a point where no services are responding. After a few minutes, it comes back and is running well. The server keeps doing this cycle, what could be ...
0
votes
2answers
663 views

what should be limit to use for IPTABLE rate limiting for a webserver

I see on my webserver some logs as follows 203.252.157.98 - :25:02 "GET //phpmyadmin/ HTTP/1.1" 404 393 "-" "Made by ZmEu @ WhiteHat Team - www.whitehat.ro" 203.252.157.98 - :25:03 "GET ...
2
votes
3answers
539 views

DDOS by several IPs with one connection [duplicate]

I have a site that was being hit with a DDOS the same time every day for the past month, and after spending a month researching and pinpointing the bug, we enacted a bash script which if the ...
2
votes
2answers
442 views

How do you stop PINGs from causing a DOS on a Linux server?

Have a CentOS-5.x box that appears to be going down as a result of PINGs. If the server gets PINGs it stops replying to ssh/http connections. Appears iptable is one approach, but I want to make sure ...
1
vote
2answers
396 views

Finding Evidence of a Denial of Service Attack (Linux)

We had a Gentoo Linux server (that was updated weekly or bi weekly) that higher ups claimed did a denial of service attack on the whole local network and brought it down. Are there any log files we ...
1
vote
2answers
5k views

HTTP server, SYN flooding, and DoS attack questions

I am making an http server in c. It is in a pre-alpha stage but seemed to be stable enough to deploy on my server and run 4 minimal websites. It has been running seamlessly for two days until this ...
1
vote
4answers
192 views

rhel-5.3->vm wordpress attack

i have a rhel 5.3 w/ few virtual machines and one of virtual pc runs cpu: intel quad 2.83 mem: 3.5G os: Linux 2.6.18-128.1.14.el5xen #1 SMP Mon Jun 1 16:09:30 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux ...