On Thu, 6 Mar 2003, Kamal Matta wrote:
thanks mr nath, but how come this would have been done ? if seems i don't have a choice but to reinstall and resetup.
Yes, _if_ you system has really been cracked, it is advised to install the system from scratch again. So first figure that out, from you description of the problem, if syslog is not working, as it should, you may have a real problem at hand. So check first why it is not working. If you determined that your system has really been cracked, them everything below applies. ;)
is it possible to reinstall the damaged area as reinstlling and resetup will be big problem for me.
Pain it will be, but to your advantage only. Many crackers will employ different tricks to re-establish control of a cracked system, which includes putting all sorts of trojan software on the system. Searching each one requires enough knowledge of the system and even then you can not completely guarantee that all security holes have been plugged on your system. So install from scratch and *** apply all the security updates released by RedHat ***. For this go to http://www.redhat.com/errata.
i am using this server for NAT/RAS/DNS/DHCP/PROXY/WEB services. i am using ipchains and setted masq on ppp and eth1 ports to allow to use this box as gateway to some users as rest use proxy settings.
You might want to boot in single user mode and note down all the configuration changes for your servers. The same can then be applied to the new and patched installation. See the security FAQs / HOWTOs for each of the servers you use, and check if your setting are opening any obvious security holes.
For a good introduction to configuring security under Linux see this HOWTO, http://www.tldp.org/HOWTO/Security-HOWTO/index.html
only recently we have started using cable internet and got one ip. could this has helped the hackers ? earlier we were using diapup connectivity. if possible please help me and tell as what precautions should i take to keep away the hackers.
A static IP only means that the intruder has more time to play around with a cracked machine, it is not that you will be safe on a dialup line, only that the chances of successful compromise are slightly less. Hence least you can do is to keep you system updated with security patches.
i will let u know what u have asked as right now my system is in use by users as rest everything is working except login. and see all details i have to boot it to linux single.
The sooner the better, you don't want intruders running inside your lan systems do you?
----- Original Message ----- From: "Tapeshwar Nath" gtapeshwar@yahoo.com To: linuxers@mm.ilug-bom.org.in Sent: Thursday, March 06, 2003 4:27 PM Subject: Re: [ILUG-BOM] Login Problem Please help
[snip]
It seems like your machine has been hacked ... and has been played around with. Can u check what glibc version you are using. and whether it has been changed..., whether your mingetty has been tampered with...Also check where your /bin/sh points to...
There are also standard softwares that come thru which you can check your system integrity. Try google search...
Here is good one to find trojons and rootkits, http://www.chkrootkit.org/
[snip]
HTH, Rajesh