Router Backdoor for When Your Upgrade Goes Awry

Hopefully this helps someone else, but it’s mostly for my own edification for if when this issues happens again. This pertains to the Netgear Nighthawk X6 | Tri-Band WiFi Router | AC3200 (R8000) but I’m sure it apply to other (similar) routers. If you’ve ever used a Netgear router, you might not have been a big fan of it’s management UI. I wanted more control over my router so I opted to go for FreshTomato. After a few months, I decided to go through the upgrade process.
/usr/bin/cat ⏎ 

Command of the Day: cowsay

cowsay is an extremly fun and super easy to use command. Just put whatever you want as an argument after the command and you’ll be greated with an ASCII cow and a speech bubble saying it. This probably isn’t installed by default, so fire up your favorite package manager and install it!
/usr/bin/cat ⏎ 

Command of the Day: sl

I think it is now……week three of working from home. Rather than get into the nitty gritty of some standard UNIX command, I thought I’d take this week to introduce you to a few fun commands. Some of these are non-standard, and by that I mean they are usually not available by default on your system. So you’ll have install it, sorry. They can be installed with any package manager, I can confirm at least with brew for macOS and apt for Ubuntu/Debian. Let’s start this off with a funny little command called sl.
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Command of the Day: grep

Boy oh boy, where to begin with grep. This one took me down a rabbit hole. grep is one of those tools that I feel has always been there; like with ls and cd. It is a command I’ve come to rely on for almost anything I do on the command line. I will say this, grep is powerful, like SUPER powerful. It’s so vast and complex that people have written multiple books about it. So before we dive in, remember that this is an overview. It won’t cover everything, because I cant. But I hope to give you some building blocks to which you can use to build greater things.
/usr/bin/cat ⏎ 

Command of the Day: cat

What a great name for a tool. Funny enough, there is a dog command, but it’s not installed by default. The original cat came with Unix version 1 in November 1971, and it replaced an older command called pr. Believe it or not, chances are, the pr command is on your machine today! That’s a new one on me. The pr command has a different output format than cat, making it a bit “prettier” because it offers a pagination filter. Anyway, back to cat
/usr/bin/cat ⏎ 

Command of the Day: chown

As with chmod, this is another program that has stood the test of time…Unix time ba dum tsh. This was also another command that was released with Unix 1, and the GNU version was released as part of Fileutils in October 1992. The chown command stand for change owner. As you may have guessed, it allows one to change the owner of a file or directory, and allows you to change the group as well.
/usr/bin/cat ⏎ 

Command of the Day: chmod

This is one of the oldest commands as it has been around since the first version of Unix that was released in 1971. The GNU version was written by David MacKenzie, the same author as head, tail, and many others that I haven’t covered yet. chmod stands for change mode. What some may consider to be file permissions were considered modes, and are still referenced as such.
/usr/bin/cat ⏎ 

Command of the Day: top

Like all great Unix commands, top has a meaning behind its name. It stands for Table Of Processes. Not surprising as it shows a wealth of information running about the system. If you’re running a Linux machine, or macOS (or some BSD variant), top is an extremely useful program. It is a task manager, err..well, more of a system monitor, but has some task manager like properties. The original program was first released in 1984 by William LeFebvre for Unix.
/usr/bin/cat ⏎