Best IT Blog

Linux / UNIX Basics

Posted in O S (375) by Guest on the August 27th, 2010


login: <user account>

password: <user password>




File Systems:

pwd: print current working directory

ls [-l] [-a]: List the contents of current directory

File attributes:

drwxr-xr-x  2 root  root  1024 Jun 4 17:01 bin/

  • d: [-dlsbc] -> [file,directory,link,special,block,char]
  • permission modes:
    • user (owner)                read
    • group    ó          write
    • others                 execute
  • Change permission mode of files or directories:
    • chmod <mode> <filenames>
    • <mode>: [ugo][+-][rwx] or an octal number
  • Change owner of files
    • chown <user>.<group> <filenames>

Linux system directories:

/                           root directory

/bin                      binary files

/dev                     device files

/etc                      configuration files and initialization scripts

/home                  root of user home directories

/lib                       programming language library

/lost+found         lost files

/proc                    Linux system information

/root                     root home directory

/sbin                     binary files for system management

/tmp                     temporary directory

/usr                      user files

/var                      various files

/mnt                     a temporary mount point

Special directories:

~                 : home directory

~<user>      : home directory of <user>

.                  : current directory

..                 : parent directory

Directory-related commands:

cd <directory>          : change directory

mkdir <directory>    : make directory

rmdir <directory>    : remove directory

File-related commands:

cp <filename> <destination>        : copy files

mv <filename> <destination>       : move or rename files

rm <filename>                               : remove files

more <filename>                           : display file by page

cat <filename>                              : display the whole file

ln [-s] <oldname> <newname>   : make links to files

I/O redirection:

<     : input

>     : output

|      : pipe

Online manual pages:

man <command>: display manual page for <command>

User Info

User information commands:

who                        : display who is logged in on the system

w                            : display who is logged in, and what are they doing

whoami                  : display current user name

finger <user>         : display information about <user>

Changing user information:

passwd    : change password

chsh         : change shell

chfn  &nb

sp;    &

: change finger information

Process & Job Control

Terminating processes or jobs:

Ctrl-C: interrupt current process

Ctrl-D: terminate file input

Ctrl-Z: suspend current process

Process-related commands:

ps [-x] [-a]: display information of processes

kill -9 <PID>

Job control:

<command> &      : run command in background

bg                           : put current suspended job into background running

fg                            : continue suspended job

jobs                         : list background jobs


alias <name> = <command line>         : assign command line to the alias

unalias <name>                            : remove alias

File Editors: joe, vi, ed, emacs, pico, …

  • Basic operation of joe:

Ctrl-KX: save file and quit

Ctrl-C: quit

Ctrl-KB: mark beginning

Ctrl-KK: mark End

Ctrl-KC: copy marked text

Ctrl-KM: move marked text

·         Basic operation of vi:

(1)    In command mode:

arrow keys    change cursor position

i                    insert (change into editing mode)

a                   append after cursor (change into editing mode)

x                   delete this character

dd                 delete this line

:w                 write to file

:q                  quit

:q!                 quit without saving changes

(2)    In editing mode:

ESC              change back to command mode

Printing commands:

lpr <file>   : print a file

lpq              : list printer queue

lprm [-]      : remove a printing job

Miscellaneous commands:

clear                             : clear screen

date                              : display current date and time

which <command>     : display the pathname of <command>

Environment variables:

set                                                         : display current environment variables

echo $PATH                                        : display current setting of PATH

<name>=<value>; export <name>   : define a variable <name>

Shell scripts ó batch files in DOS

Local Configuration Files:

~/.cshrc         : C Shell rc file

~/.login          : Login scripts

~/.plan           : personal plan à for finger

~/.forward     : e-mail forward list

Becoming superuser:

su <root>
sudo <command>

Useful tools:

find <dir> [-name <filename>] [-print]            : find <filename> from <dir>

grep <string> <files>                             : search <string> in <files>

diff <file1> <file2>                                 : display the differences between <file1> and <file2>

Comments Off on Linux / UNIX Basics

PowerPoint – Blackberry Enterprise Server

Posted in eMail (66),Sample - IT Spreadsheets - PowerPoints (251) by Guest on the August 25th, 2010
Comments Off on PowerPoint – Blackberry Enterprise Server

Sanctions for Regulatory Non-Compliance

Posted in Compliances (1300) by Guest on the August 21st, 2010

There are penalties for stakeholders; CISO is liable.

The first column indicates when the year when the regulation came into existence

The next column shows the fine the maximum fine.  As you can see, there are some hefty fines associated with non-compliance. 

This is driving behaviour.

The next column shows the imprisonment that is associated with non-compliance to each of these regulations.  This is also driving behaviour.

The last column shows the other negative consequences of non-compliance.

For PCI, rescinding the right to accept credit card data is devastating.  It is much worse than any fine that Visa / MasterCard to impose


Date of




HIPAA 1996 $250,000 10 years Health
GLBA 1999 $100,000 per incident 5 years Financial
PCI 2005 $500k per incident + $100k if VISA is not notified None—Rescind the right to accept credit card payments Credit Card Security

Others to consider:

AR 335–15, Management Information Control System

DA Pam 25–1–1, Information Technology Support and Services

DODD 5015.2, Department of Defense Records Management Program


Comments Off on Sanctions for Regulatory Non-Compliance

Excellent windows Tweaks and Internal Information

Posted in O S (375) by Guest on the August 20th, 2010

Great site for Tweaking Windows and understanding some of the internals.

Comments Off on Excellent windows Tweaks and Internal Information

Viruses, Worms and Trojan Horses

Posted in Security (1500) by Guest on the August 19th, 2010
Author unknown it was still worth publishing
         program that reproduces by attaching to another program
         may damage data directly or it may degrade system performance by taking over system resources, which are then not available to authorized users
         an independent program that reproduces by copying itself from one system to another, usually over a network
         may damage data directly, or it may degrade system performance by consuming system resources and even shutting down a network
         Trojan horse
         an independent program that appears to perform a useful function but that hides another unauthorized program inside it. When an authorized user performs the apparent function, the Trojan horse performs the unauthorized function as well (often usurping the privileges of the user)
Malicious Programs
         Those that need a host program
         Fragments of programs that cannot exist independently of some application program, utility, or system program
         Self-contained programs that can be scheduled and run by the operating system
         Entry point into a program that allows someone who is aware of trapdoor to gain access
         used by programmers to debug and test programs
         Avoids necessary setup and authentication
         Method to activate program if something wrong with authentication procedure
Logic Bomb
         Code embedded in a legitimate program that is set to “explode” when certain conditions are met
         Presence or absence of certain files
         Particular day of the week
         Particular user running application
Trojan Horse
         Useful program that contains hidden code that when invoked performs some unwanted or harmful function
         Can be used to accomplish functions indirectly that an unauthorized user could not accomplish directly
         User may set file permission so everyone has
         Program that can “infect” other programs by modifying them
         Modification includes copy of virus program
         The infected program can infect other programs
         Use network connections to spread form system to system
         Electronic mail facility
         A worm mails a copy of itself to other systems
         Remote execution capability
         A worm executes a copy of itself on another system
         Remote log-in capability
         A worm logs on to a remote system as a user and then uses commands to copy itself from one system to the other
         Program that secretly takes over another Internet-attached computer
         It uses that computer to launch attacks that are difficult to trace to the zombie’s creator
Virus Stages
         Dormant phase
         Virus is idle
         Propagation phase
         Virus places an identical copy of itself into other programs or into certain system areas on the disk
Virus Stages
         Triggering phase
         Virus is activated to perform the function for which it was intended
         Caused by a variety of system events

   < /span>Execution phase

         Function is performed
Types of Viruses
         Attaches itself to executable files and replicates
         When the infected program is executed, it looks for other executables to infect
         Lodges in main memory as part of a resident system program
         Once in memory, it infects every program that executes
Types of Viruses
         Boot sector
         Infects boot record
         Spreads when system is booted from the disk containing the virus
         Designed to hide itself form detection by antivirus software
         May use compression
Types of Viruses
         Mutates with every infection, making detection by the “signature” of the virus impossible
         Mutation engine creates a random encryption key to encrypt the remainder of the virus
         The key is stored with the virus
Macro Viruses
         Platform independent
         Most infect Microsoft Word
         Infect document, not executable portions of code
         Easily spread
Macro Viruses
         A macro is an executable program embedded in a word processing document or other type of file
         Autoexecuting macros in Word
         Executes when Word is started
         Executes when defined event occurs such as opening or closing a document
         Command macro
         Executed when user invokes a command (e.g., File Save)
E-mail Virus
         Activated when recipient opens the e-mail attachment
         Activated by open an e-mail that contains the virus
         Uses Visual Basic scripting language
         Propagates itself to all of the e-mail addresses known to the infected host
Comments Off on Viruses, Worms and Trojan Horses

Sample Excel – Technical Reference Model Sample Descriptions

Posted in Sample - IT Spreadsheets - PowerPoints (251),Security (1500) by Guest on the August 18th, 2010
Comments Off on Sample Excel – Technical Reference Model Sample Descriptions
Next Page »