An almost invisible ssh connection
----------------------------------
In the worse case if you have to ssh on a box, do it every time
with no tty allocation
ssh -T user@host
If you connect to a host with this way, a command like "w" will not
show your connection. Better, add 'bash -i' at the end of the command to
simulate a shell
ssh -T user@host /bin/bash -i
Another trick with ssh is to use the -o option which allow you to
specify a particular know_hosts file (by default it's ~/.ssh/know_hosts).
The trick is to use -o with /dev/null:
ssh -o UserKnownHostsFile=/dev/null -T user@host /bin/bash -i
With this trick the IP of the box you connect to won't be logged in
know_hosts.
Using an alias is a good idea.
Erasing a file
--------------
In the case of you have to erase a file on a owned computer, try
to use a tool like shred which is available on most of Linux.
shred -n 31337 -z -u file_to_delete
-n 31337 : overwrite 313337 times the content of the file
-z : add a final overwrite with zeros to hide shredding
-u : truncate and remove file after overwriting
A better idea is to do a small partition in RAM with tmpfs or
ramdisk and storing all your files inside.
Again, using an alias is a good idea.
The quick way to copy a file
----------------------------
If you have to copy a file on a remote host, don't bore yourself with
an FTP connection or similar. Do a simple copy and paste in your Xconsole.
If the file is a binary, uuencode the file before transferring it.
A more eleet way is to use the program 'screen' which allows copying a
file from one screen to another:
To start/stop : C-a H or C-a : log
And when it's logging, just do a cat on the file you want to transfer.
Changing your shell
-------------------
The first thing you should do when you are on an owned computer is to
change the shell. Generally, systems are configured to keep a history for
only one shell (say bash), if you change the shell (say ksh), you won't be
logged.
This will prevent you being logged in case you forget to clean
the logs. Also, don't forget 'unset HISTFILE' which is often useful.
Some of these tricks are really stupid and for sure all old school
hackers know them (or don't use them because they have more eleet tricks).
But they are still useful in many cases and it should be interesting to
compare everyone's tricks.
