Real Hackers Use 'netcat' To Transfer Files

I needed to copy a file between two computers on the same LAN as fast as possible, but I didn't have any USB flash drives available. To solve this problem, I used the 'netcat' command to pipe the file directly between the two computers over a raw TCP connection.
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[@RobertElderSoftware]

"Why not use SSH or rsync?" I've already responded to this question a few times in the comments, but I keep seeing people asking the same question. The answer, (as mentioned in the video) is that I didn't have time to set up or configure an SSH server in this scenario. Some people have said "that's not realistic, SSH is usually already installed by default", and it's true that SSH is usually installed by default, but just because SSH is already installed, doesn't mean it's already set up to allow your user account to access it! In fact, the most realistic scenario where this 'netcat file transfer' is realistic is exactly *when* you are setting up your credentials with SSH. In order to install your SSH key onto the remote machine, you need to distribute your public key onto it. This will either mean using a USB flash drive, or sending the public key to an admin who already has shell access. For a computer on your local LAN, it's easier and faster to just use netcat. Personally, I literally use this exact technique to distribute my public key onto a remote machine on my LAN whenever I'm doing something like setting up Linux on an old laptop or a desktop server. Once the public key is copied, then I can just switch to using SSH. It's easier than bothering to try and find a USB flash drive. I have also used this technique occasionally when I just want to quickly transfer a large file, like a virtual machine image or something between two computers on the LAN, and I don't have SSH access already set up between these two computers, and I don't want to bother setting it up. And yes, for the record, this method of transferring the data is *COMPLETELY UNENCRYPTED*. If you need to transfer a file using encryption, use SSH.

[@itsme7570]

Socat?

[@Comeyd]

You can pipe through more than one thing… you can always use GPG with a password to encrypt your pipes data too! Heck, through gzip in there too to compress it as well! Throw pv somewhere in the mix to monitor transfer progress as well! You can even use tee to complete the sha256 at the same time so you have your hash as soon as the transfer completes! Chaining *nix commands together with pipes is incredibly powerful!

[@AL_Mir29241]

You're already SSH'd into a machine... You can use SCP.. with encryption and compression :/ why do it this way???

[@josephdiazg]

​@@AL_Mir29241read the fricking comment man 💀

[@wizpig64]

Thank you for the public key idea, implementing this would tidy up my workstation deployment automation so well!

[@davidsalvador8989]

"But then I remembered the command netcat!" "After 45 minutes of reviewing the netcat --help page and trying to get the command correct it was finally being sent and i was being arrested."

[@RobertElderSoftware]

haha, this made me lol

[@laughingvampire7555]

or the FBI got to you because you asked chatGPT for how to use netcat to hack some server

[@Razy_exe]

Made you.. what?​@@RobertElderSoftware

[@blzr8]

Man page go brrrrrrrrr

[@NickyDekker89]

Practice makes perfect.

[@Devire666]

1 GB text file? Wow, those have to be some really big secrets!

[@lifelover69]

it contains the last 6 digits of pi

[@-na-nomad6247]

The extention doesn't matter. It will work even if not text.

[@mrbutish]

They had photos and videos in the TXT file 😂😂

[@mrbutish]

I just noticed the file had secrets on Satoshi nakamoto and nuclear laugh codes 🤣

[@LeGuJ]

But, gotta ask ... Is it your favourite Linux command?

[@RobertElderSoftware]

This is my favourite comment.

[@roeniss]

you made my day 😂

[@rotteegher39]

I haven't realized it's the favorite linux command guy until reading your comment

[@benargee]

Leave the man alone. He has dementia and wakes up every morning not remembering the last. Every day he discovers his favorite Linux command.

[@der.Schtefan]

​@@benargeeI think he is just secretly Latino and has a lot of "favorites" and "the only love" ;)

[@timr6235]

cli is green -> shit is serious, and then he remembered netcat, brother you have it in you.

[@maxxroach8033]

“>” is not a pipe. It’s an overwrite redirect. “|” is pipe

[@BoostedFA]

I caught that too. In his next image, he used the pipe symbol.

[@sith4life375]

You usually hear pipe to a file, not redirect to a file.

[@AV_YOUTUBE_202X]

Technically it's a shell-aware-stdout-content-overriding-file-writeloop. Get it right. I don't want to hear any shorter terminology

[@jasonmorris9330]

"Then I remember that the routing tables weren't configured correctly and I didn't have access to the routers to add the correct routing tables"

[@Heopful]

then i remembered i had no idea what any of that meant anyway so i decided to do what I normally resort to in times of trouble and went to study some incoming packets in realtime using tshark

[@SalivatingSteve]

@@Heopfultshark? Is that the terminal version of Wireshark?

[@Psi141]

You dont need any special routing tables to connect to another laptop in lan

[@der.Schtefan]

If you're in the same situation on a modern Windows: Netcat is often not installed, but Powershell has a nc alias. In case of an old Powershell on a locked down server install, you can use the fact that you can use .NET objects on the Powershell command line to open network connections (or transfer files via http)

[@rohithkumarbandari]

Well most high stakes servers are gonna use linux anyway so...

[@cinderwolf32]

I like ncat for windows

[@JordanPlayz158]

​@@rohithkumarbandaritrueeeee

[@ryanwalker4660]

just a reminder this traffic will not be encrypted, by default

[@CYBER-HERO]

You can encrypt it. Netcat support RSA encryption, but netcat dont have any default certificate or key, you need to create it.

[@human4566vv]

yes like encrypting something is very hard in Linux right? all you have to do is pipe the file into a encrypter and decrypt it on arrival,

[@rkidy]

@@human4566vvbros fighting ghosts… who said it was difficult?

[@besterspieler2285]

​@@human4566vvif it's a "super secret Hacker file" its probably already encrypted

[@core36]

@@human4566vv that’s why he said „by default“

[@daniellittlewood8471]

Unfortunately, because I piped cat to netcat rather than redirecting standard input, the first laptop ran out of memory and I was caught :(

[@FriendlyNeighborhoodNitpicker]

I absolutely hate it when people cat something through a pipe instead of just using a file redirection < on the receiving side. I see it so often in scripts and forums online, and it boggles my mind.

[@cmroosen]

Can you explain how “cat file | netcat” could cause out of memory? As I understood a pipe just buffers and blocks when full so it doesn’t load complete file in memory. It’s still a useless cat though 😼

[@daniellittlewood8471]

@@cmroosen You're just right, my mental picture was completely off!

[@EmrecanOksum]

Highly sensitive files transferred in plaintext.

[@quinndirks5653]

Isn't it plaintext?

[@EmrecanOksum]

@@quinndirks5653 correct

[@greycell2442]

you can pipe encrypt or pre-encrypt. it's all painless and fast compared to setting up ssh

[@rya3190]

Hey, it ain't my sensitive files...

[@taahaseois.8898]

@@rya3190 Exactly.

[@SuperOblivionfan]

Yoo u gotta make more like this, better format than the other vids. Entertaining and educational :D

[@RobertElderSoftware]

I'd like to, but there are only so many hours in the day.

[@askholia]

Love your videos! It is amazing how often I just forget about netcat existing. I am so SSH brain'ed at this point. It was great to see this.

[@thirtysixnanoseconds1086]

entertaining and informative!!! thanks

[@brunobmartim]

Totally agreed with you

[@pjj7466]

Wowww. I was thrilled and suprised at the same time. Nc is favourite linux command now.

[@RobertElderSoftware]

This is my favourite comment.

[@riccardobassini9452]

So glad you finally got it moving. Can't wait to see the remote controller and the machine properly working. Keep up the good work!

[@Maza-qw8pc]

videos dope, i learned something and already new some. making me more confident brody.

[@JacobP81]

That is so cool. I could probably use that. Not for malicious uses but just when I need to transfer a large file between computers.

[@justadude8716]

Amazing tutorial!

[@overclucker]

The most versatile technique IMO is to use screen's logging feature. For binary files: cat file | gzip | base64 Directories: tar cjf - directory | base64 you can extract them from your log later. If the system doesn't have any form of encoder available, you can paste an encoder function.

[@RobertElderSoftware]

Using 'tar' would definitely be useful for copying directory structures, but I don't see why you'd need 'screen' or 'base64' for this example. If you don't have SSH access, then what advantage would 'screen' provide? If you do have SSH access, then you can just use 'scp' without the need for base64 or screen. On the other hand, if it's an air-gaped system, but it has access to a printer, base64 would work great to just print your data to paper and carry it out.

[@CurseTheVulgar]

@@RobertElderSoftware Late to the party, but I think he meant that if you're using screen on your computer for your terminal work, you can enable the scrollback logs thus capturing the output on the remote system. So by using tar and outputting the entire resulting archive as base64 to stdout on remote, you capture it in your local screen terminal history which you can then save/dump/process, no additional networking like nc required. (The same principle would apply with any GUI terminal like Gnome Terminal, rxvt, Windows Terminal etc. It's a solid exfiltration technique, and leaves less traces/less chance of IDS/EDR interference since there are no extra connections being made.)

[@whitepaperkat67]

You can use rsync or another utility called croc

[@chang112x]

The netcat command is my favorite linux command. I use the netcat command to transfer files...

[@chandler404]

Please use scp or rysnc to transfer files...

[@UltirianHeavyIndustry]

Crisp and informative.

[@N0_1_in_particular]

*highly sensitive files*

[@DrkRevan]

I very much enjoy your content dude, awesome.

[@Tom.malucao]

Really good content! Just leave the ‘this is my favorite command’ out of them plz :)

[@RobertElderSoftware]

This is my favorite comment.

[@SuRFaceGoD]

learning commands with a story🔥

[@jeevankumarn6581]

very well explained,thank you

[@snopz]

scp left the chat

[@Tom-uy4io]

If you have the time to set up a SSH server, yes. Also, if you need encryption, yes. But remember what he said? No time to set up a SSH server.

[@pleonexia4772]

Seen a few of your shorts. This one won you a sub

[@babblo]

The Unix way

[@ahmetmutlu348]

cygwin provdes this tools to windows...

[@paulszabo8222]

People in the comments are missing "there wasn't enough time to setup ssh". And in this hypothetical situation why would you even care about protecting the data in transit?

[@teebob21]

exactly. cp _host_ file _destination_ copied_file

[@akex067]

I usually use python http server module and access via web

[@ralphclark]

That takes much longer than just typing a short ncat command on each computer. Learn netcat. It has dozens of uses.

[@demonman1234]

@@ralphclarkTrue. You could also setup a reverse shell with netcat (quite simple to do), ofc you probably don’t want to do this but the option is there.

[@ralphclark]

@@demonman1234 that's not very secure. If you need remote shell access, use ssh instead, otherwise you're opening up an exploitable security hole.

[@t58beare]

​@@ralphclarkIt takes the same amount of time if not shorter than typing the nc command... python3 -m http.server

I usually use curl to upload the file to one of my web servers. It's just protected by basic auth, so I can hit it from anywhere with an internet connection, and it's protected by TLS unlike a plain netcat socket.

[@t58beare]

That's a great way to get busted unless you have compromised someone elses server/VPS to utilize... his laptop is right next to him, so just transfer the file on the local network instead of leaving artifacts and logs with connections to your web server where they can easily find out your pub IP.

[@morsine]

Oh nice. I've never heard of this, this will be very useful!!

[@FuzzyGhost]

This is cool, unfortunately I'm going to forget this, and you can't add shorts to a playlist.

[@lurtiskoe]

ummm, yes you can? at least i can. tap the 3 dot menu on the video while logged in. its right there.

[@Raaampage]

Awesome I love your content

[@FlatEarthDisciple]

Is that cool-retro-term? lol. I can't live without it.

[@Garlic_Bread69]

Port 1234 goes fire tho

[@0xtz_]

I remember the CTF days it was my only way to transfer the flag file 😂

[@davidvernon3119]

Croc is pretty handy for this too. It’s my favorite Unix command.

[@noahreeverts465]

The netcat command is my favorite linux command.

[@RobertElderSoftware]

This is my favorite comment.

[@powerdude_dk]

​@@RobertElderSoftware ah ah ahhh, you can only have 1 favorite comment! 😂

[@bromophenol2469]

The netcat command is my favourite command.

[@RobertElderSoftware]

This is my favourite comment.

[@fabriziop.3360]

I saw lot of people wonder why using this instead of ssh.. 15-20 years ago was more common using netcat to transfer, instead of ssh, especially on slow machine that could go slower with encryption

[@mohammedissam3651]

This only works on the same network or the internet

[@kopuz.co.uk.]

what did you expect?

[@kahnfatman]

Thank you! Now this is my linux favorite command.

[@Passco666]

Wow super tip. Thank you

[@Fullflexno]

Cool framing on video!

[@Dhalucario]

There is also some other very neat tools for file transfer. Local Send on the desktop and croc for the terminal.

[@Somens8Dworld]

this should be on the local area network. if you want some gui I have built one I call it FileSync. it syncs your shared folder for every PC or mobile you connect. everything is linked with everything. you can transfer files folders you can get a full clipboard access everything is local, no ads free open source

[@zsomborgyenge4359]

the -q option not always necessary some implementation don't even have it

[@RobertElderSoftware]

It's been a while since I made this video, but I do recall something about this being the case. Some important options to the 'netcat' command are not well standardized and work differently on certain platforms (mac for example). If anyone else has additional corrections/tips, feel free to post them as comments.

[@altaccount648]

A cool way to teach people about the countless linux packages

[@ChrisPinCornwall]

Thank you. I never knew that.

[@lucss21a]

Gonna save it for later. I often use termux and my openSUSE desktop for Linux stuff

[@GoogleUser2311]

I got an idea. Every distro has some or the other http server software installed, even if you have python you have http.server. that can be used for file transfer.

[@user4gent416]

Great for sending simple files anyway. Also it should be fine on a private and safe network

[@resultingrun5928]

Similar to magic-wormhole. This is a bit more arguments but I bet predates the other command.

[@enigmatico6209]

You forgot to clear your shell history in the other computer. You left the tracks behind you.

[@meeshoot3850]

Awesome ! Thanks 😘

[@thelonestead]

dd over ssh to backup a partition is fun, especially when when you need to resume a previously failed transfer. Now, what was the difference between 'skip' vs 'seek'?

[@bigl9527]

I use this to stream an AiO PC camera from remote location to my MPV so I acn use it as cctv

[@ocsrc]

I remember using 2 DOS commands and a special 25 pin cable to make my desktop the send and the 286 laptop the receive computer I copied Windows 95 to the laptop and it took about 2 hours It worked I was shocked

[@louistiches4810]

Lol, I am pretty sure netcat should not be installed for that very reason. Nobody will steal my corgi memes on my netcatless servers. Awesome video and people should be made aware of ways non root users can potentially transfer stuff on servers that are not locked down. But then again, who uses servers anymore.

[@boneappletee6416]

😂 Lol I'm sorry... "who uses servers anymore" is that meant to be sarcasm/rage bait?

[@aliwalil4160]

Video should have started with "The netcat is my favorite Linux command. I use the netcat command to transfer secret gov files to my laptop" :D

[@MrKarlheinzspock]

But you have to check if it's gnu netcat or bsd netcat first, because of incompatible command line arguments.

[@JohnDoe-rx3vn]

You can also encrypt or archive data before and after netcat

[@ONEGOALONEJOURNEY]

scp is also a good option

[@Tom-uy4io]

If you have the time to set up a SSH server, yes. Also, if you need encryption, yes. But remember what he said? No time to set up a SSH server.

[@christopherroberts2986]

socat is my favorite tool, netcat is my second favorite

[@robersonrodrigues673]

How would be a transfer from linux to windows netcat?

[@lucasew]

And if you need to send many files at once you can do that with tar and view transfer size using pv

[@HawK40x]

I have a busybox system Linux and the shell I get is read only also I don't know root password but there's a file I have to remove/edit or anything which could deny the affects of it

[@Hackerfrank]

That is awesome

[@brazni]

This is my favourite RobertElderSoftware short

[@RobertElderSoftware]

This is my favourite comment.

[@kurdm1482]

I love you hope u the best ❤

[@veloriba]

and don't forget to add a whitespace at the beginning of the command

[@littleharry7977]

Awesome

[@DanelonNicolas]

netcat is my favourite command

[@RobertElderSoftware]

This is my favourite comment.

[@smit17xp]

This will be useful

[@Mr_Jort]

yes but netcat is insanely noisy and is a huge red flag if you're getting alerts about it on blue team.

[@kimo4530]

should use fnp or rmx for bridging port

[@min3craftpolska514]

Clear your bash history!

[@zilog1]

Not on that cat versions are the same and lots of time this doesn't work because certain flags have been disabled on recent updates making it difficult to do this on more up-to-date machines

[@JustABitBetter-h7e]

you do know the target pc needs to have netcap installed on right??

[@chunky_sister]

It’s a text file. Copy… paste…

[@cinderwolf32]

Between computers

[@ChapalPuteh_]

old but good

[@BtaraDev]

One could even say that it is "your favorite linux command"

[@lonixlon]

Increases the size by 1/4 but I would base64 encode it

[@converter]

A hacker without usb

[@micmacha]

This is how word problems should have been.

[@burstfireno1617]

hmm damn doesnt seem to work on macOS terminal

[@lauriran]

This unnecessary abuse of cat needs to stop!

[@xv3ei]

What's up hackers!

[@anthonygreene757]

“After a quick hash check and I was outta there”…

[@spreadthesmile454]

i did the same from my termux to my lap...file was transferred but there is no content inside it ...WHY???

[@superhawk20002]

Or you can be a better hack and remember a USB flash drive. By the time I set up anything that will realistically transfer without trace, I could just run out and grab/buy/steal/whatever a USB drive. Thats mostly because it'd prob take me forever to get netcat or SSH or anything else working correctly.

[@DarkMachine-1234]

question what about a cable simply lug it in to both laptops and transfer it over done. much simpler

[@RobertElderSoftware]

This is possible, but it's really solving a different problem than the one emphasized in the video. Using 'netcat' to transfer solves the application layer problem of what software will move the data. Using a different cable solves the link layer problem, which is already presumed to be solve in this scenario (since the two computers are on the same LAN).

[@bountyjedi]

If I had a penny for each time I used this for quick and dirty file copies. Also to send files between friends on the same network, lol.

[@veera_tamilan]

I have a doubt is this also works in wAn or only in local network

[@tander101]

You're very Canadian

[@timrosulnik1588]

I would mount a usb drive and copy file to it. It would be faster and more reliable.