When you get Linux training, be sure that it is focused on how to use Linux commands. Also, if you are interested in getting Linux certification, you need to know how to use Linux commands to be able to pass, not Linux GUI utilities.

Linux Tips – How to Use Linux “Patterns” (Linux Wildcard characters)

Some Linux documentation uses the term “pattern” to refer to Linux wildcard characters.

Wildcard characters are used in a “pattern” to cause a Linux command to work on multiple items, such as multiple directories and files in the Linux file system.

The two Linux wildcard characters are the * (asterisk) and ? (question mark).

Using an * (asterisk) with a Linux Command

An * (asterisk) is used in a pattern to represent “all” characters of an item (directory or file).

The Linux command below shows an example of the using the cp (copy) command to copy all (because of the * without any other letters or numbers) files in the current directory into the directory named memos.

]# cp * memos

Linux Tips: Keep in mind that Linux commands are “case sensitive”. Always type the letters in upper or lower case, as shown.

Linux Tips: Also, be sure to use spaces where they are shown. For example, in the Linux command above, you need a space (just a single space) between cp and the * and you need a single space between the * and memos.

The * (Linux wildcard character) can be combined with one or more letters at the front of it or after it.

The following Linux command is an example of the using the cp (copy) command to copy all files in the current directory beginning with the letter r into the directory named memos.

]# cp r* reports

The Linux command below copies all files ending in “sxw” into the directory named weekly.

]# cp *.sxw weekly

The next Linux command copies all files containing “mem” (anywhere in the file name) into the directory named monthly.

]# cp *mem* monthly

Using a ? (question mark) with a Linux Command

The ? (question mark) is used in a pattern to represent a single character.

The Linux command below shows an example of the using the mv (move) command to move files that have a single character and end in “cfg” into the directory named june.

]# mv ?.cfg june

The following Linux command moves all files beginning with “month”, and having two characters after “month”, and ending in “sxw”, into the folder named years.

]# mv month??.sxw years

To learn how to use Linux commands the easy way, you can watch Linux video tutorials. When you work with Linux videos, you can actually see Linux commands being run and hear a detailed description of why you need to run a certain Linux command.

Another benefit is that you can also see the output of the Linux command and hear a description of what the output means.

After seeing how to use Linux commands, you can run them yourself – to get practical Linux training.

Keyloggers, as a surveillance tool, are often used by employers to ensure employees use work computers for business purposes only. Unfortunately, keyloggers can also be embedded in spyware allowing your information to be transmitted to an unknown third party.

A keylogger is a program that runs in the background, recording all the keystrokes. Once keystrokes are logged, they are hidden in the machine for later retrieval, or shipped raw to the attacker. The attacker then peruses them carefully in the hopes of either finding passwords, or possibly other useful information that could be used to compromise the system or be used in a social engineering attack. For example, a keylogger will reveal the contents of all e-mail composed by the user. Keylogger is commonly included in rootkits.

A keylogger normally consists of two files: a DLL which does all the work and an EXE which loads the DLL and sets the hook. Therefore when you deploy the hooker on a system, two such files must be present in the same directory.

There are other approaches to capturing info about what you are doing.

Some keyloggers capture screens, rather than keystrokes.
Other keyloggers will secretly turn on video or audio recorders, and transmit what they capture over your internet connection.

A keyloggers might be as simple as an exe and a dll that are placed on a machine and invoked at boot via an entry in the registry. Or a keyloggers could be which boasts these features:

Stealth: invisible in process list
Includes kernel keylogger driver that captures keystrokes even when user is logged off (Windows 2000 / XP)
ProBot program files and registry entries are hidden (Windows 2000 / XP)
Includes Remote Deployment wizard
Active window titles and process names logging
Keystroke / password logging
Regional keyboard support
Keylogging in NT console windows
Launched applications list
Text snapshots of active applications.
Visited Internet URL logger
Capture HTTP POST data (including logins/passwords)
File and Folder creation/removal logging
Mouse activities
Workstation user and timestamp recording
Log file archiving, separate log files for each user
Log file secure encryption
Password authentication
Invisible operation
Native GUI session log presentation
Easy log file reports with Instant Viewer 2 Web interface
HTML and Text log file export
Automatic E-mail log file delivery
Easy setup & uninstall wizards
Support for Windows (R) 95/98/ME and Windows (R) NT/2000/XP

Because a keylogger can involve dozens of files, and has as a primary goal complete stealth from the user, removing one manually can be a terrifying challenge to any computer user. Incorrect removal efforts can result in damage to the operating system, instability, inability to use the mouse or keyboard, or worse. Further, some key loggers will survive manual efforts to remove them, re-installing themselves before the user even reboots.