[bittorrent] BT, Nats, and hackers at the door...

Kenneth Porter shiva at sewingwitch.com
Mon May 30 00:35:06 EDT 2005


--On Sunday, May 29, 2005 6:54 AM -0400 Bill Cox <bill at viasic.com> wrote:

> I've got random password guessers from France and
> the Netherlands hacking the ssh port.

Note that they are *only* hacking port 22. Move ssh to another port (it's a 
simple edit to the config file) and the attempts stop.

Recent Linux distros don't listen for services unless you override the 
default configuration. Part of the mission of XP's SP2 was to change the 
default firewall to block inbound ports, making up for Windows' habit of 
listening on random ports because services needed to boot do so.

(MS claims that with Longhorn it will put more effort into enforcing the 
principle of Least-User Access (LUA), similar to the common Linux practice 
of doing as much as possible without root privilege. That means a lot of 
sloppy programs that need Administrator access (eg. to write files in the 
Program Files hierarchy) will break, just as the stronger firewall of SP2 
broke some sloppy apps.)

IPv6 has a larger port space and a larger address space, far too large for 
a  port scanner to have any hope of locating listening ports without prior 
knowledge of your network. You should endeavor to choose random addresses 
within your (large) assigned address space to make it harder for automated 
scripts to find your internal servers. (This in addition to other security 
practices. Practice defense in depth by putting more than one obstacle in 
the way of crackers.)



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