Category Archives: Security

>DoD wipe and softwares

Tweet>This is Department of Defence wipe.This is methodology of erasing all ofthe data off of the drive. This is one of data sanitization standard.Destruction of data from disk is required if somneone want to escapefrom forensic data recovery. I prefer DBAN(http://www.dban.org/) forthis purpose.

>Connection tracking in linux

Tweet>Connection tracking is done to know the state of specific connection.Firewall that understand connection tacking and allow to implementrule on that basis, is known as statefull firewall. Iptables can alsoimplement rules on tracked connection known as state, which can beimplemented through state match.Connection tracking is done by special framework in the kernel knownas conntrack. conntarck… Read More »

>TCP Wrapper Determine TCP Wrapper Support

Tweet>TCP Wrapper is a host-based Networking ACL system, used to filter network access to our linux system. Remember libwrap is the actual library that implement TCP Wrapper. But How we will determine which daemons support TCP Wrapper, i mean which server application are compiled with libwrap? . Use the following command  root# egrep libwrap /usr/bin/*… Read More »

>Lock console in linux

Tweet>Suppose you are working in text mode may be in console or ,remotely using telnet or ssh and you want to lock your screen of working. vlock command is used for this purpose. For example root# vlock     This tty is now locked.      Please enter the password to unlock.Supplying password will unlock the screen. If you… Read More »

>How to block pen drive in linux?

Tweet>The easiest way to disable usb storage device in linux is create following file    /etc/modprobe.d/no-usb And add following line inside the file   install usb-storage /bin/true Cheers usb-storage device blocked for your linux system now.  I done this on my RHEL 5.4 system.

>Lock account in linux using pam_tally or pam_tally2

Tweet>pam_tally pam module can be used to lock a account after centain number of failed login attempt. For example if you want to lock user after 3 failed login attempt. Then configure you /etc/pam.d/system-auth file in following ways         auth     required     pam_tally.so  onerr=fail deny=3(Remember to put this line above the line auth    required pam_unix.so)         account  required    … Read More »

>Lock account in linux

Tweet>To lock a user account in linux following command can be used             root#passwd -l     For example              root#passwd -l user1             Comand will lock user1, i mean user1 cant login on system now.    To get status of locking status , we can use passwd command in following way            root# passwd -S    For example            root# passwd -S… Read More »

>Be aware of anonymizer sites when configure proxy server.

Tweet>No matter how secure in your proxy configuration, what if someonebypass your proxy. There a number of anonymizer sites and software,that hides your ip address and content while surfing net.Tor(http://www.torproject.org/) is one of software that i used. Youcan try your proxy configuration by accessing https://www.tor-proxy.net/and clicking on option “Surf Anonymous Now withtor-proxy.net-Express”. And Tor is… Read More »

>Turn off window machine from remote linux machine

Tweet>Using samba you can  turn off windows machine from remote linux machine.Use net rpc command in following way        net rpc SHUTDOWN -I <windows machine ip>   -U < windows username> For example to shutdown windows machine with ip 192.168.5.5 with username administrator , use following            root# net rpc SHUTDOWN -I 192.168.5.5 -U administrator