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Maybe they left the debug symbols because they knew that even when you disassemble it, you won't be able to extract any information that could help the victim. I.e. it was a "flex".

Honestly, the large font size is useful on larger screens as well! Much, much easier to read.

Considering the part that causes actual harm is an unobfuscated *bash script,* it's pretty safe to say that leaving symbols in their generic encrypt/decrypt binaries wasn't a consideration.

Keep the cybersecurity stuff coming 😎

They made the binaries easy to use because they wanted you to know that there is no backdoor, you need to get (ie. pay for) the private key.

Thank you LLL

Great video, this has been on my mind though: Why would a ransomware writer want to obfuscate their code? If their main goal was to collect ransom, and the program was cryptographically secure, wouldn't they want to lay out everything they did in an easy to understand way? Beeing able to see exactly how I was pwned would give me at least a little bit more confidence that I would get a key in exchange for money.

Thank you for the big fonts!! I wish the other KZfaqrs would do this more: I only consume content from my phone and it’s always hard to read.

Thank you triple L. Loving the cyber security content! Keep it coming.

3:57 *Missing summary:* There are two types of encryption: * symmetric, and * asymmetric. *Symmetric* cryptography uses the *same key* for encryption and decryption. *Asymmetric* cryptography has the *key split in half:* a public key and a private key.

common lowlevellearning W

Great video! 4:14 Large font is very much appreciated but 64 pt is maybe a tad TOO large. 48 pt or 56 pt might be a better compromise. 5:32 Also, maybe make your camera be a slightly smaller circle and move it up to the right so it doesn’t obscure the code

very nice code! I've seen corporate code that looked worse than this malware. Also: security lives from openness. The symbols were left in, so you could read it. And if you had found a bug, only then they could have improved your malware ^^

I think they can leave the debug on because anyone analyzing the binaires will just learn that he cannot actually decrypt the files without the private key. The sooner the victim realizes that he cannot decrypt the files without the private key, the better for the scammer. The scammer could truly send the source code that it wouldn't matter. As for obtaining the private key form the public key, that is possible in theory. However, you won't be able to find the private key in practice unless the key is way too small (which is unlikely) or has been made by a program that is way way too predictable in how it generates its keys (and you know or guess that that program has been used to create the key) . You could wait until quantum computers with as many quantum bits as the public keys are a real thing (and boy that will be a mess when they reach that stage...) but that might be a long wait... As for using modern supercomputers, you are very unlikely to find the private key with them unless it was generated using some weak algorithms.

Thank you for the font size! - and also for the great content in general 🙂

I just wanted to take a moment to express my appreciation for your incredible KZfaq channel. Your dedication to teaching low-level programming concepts and techniques is truly inspiring,. I would love to hear your personal story about how you learned reverse engineering, and any tips or advice you have for people who are just starting to explore this topic, and thank you.

Thank you LLL!!! Seriously bro, that move is next level! That is how you take care of the peeps consuming your content. This is the first video I have seen of yours but I have subbed and liked this vid. Keep killing it!

This part of the malware is not the valuable part. This is just some basic encrypt / decrypt software that probably took them like half a day to make. Hell I'm surprised they didn't provide a readme / documentation for how it works. After all, their goal is to convince you that you'll get your stuff back if you pay the ransom. The real important part is how they got the files onto your server and ran them. That's the secret part that I'm sure they'd want to protect.

Yessss!! More security stuff! I'm trying to learn it, but it's tough, lots to learn!

Great content man, nice work!

It seems like the authors took "security through obscurity isn't security". I mean, having it not obfuscated probably lets the victims know there is no other way than paying up, and prevents wasting everyone's time I guess. And it also makes it abundantly clear that the only way out is the private key, and could also be a way to tell "lmao it's so simple, babies could write this encrypt binary, get rekt lol", so maybe a flex there too, I guess? This shows that the actual "malware" isn't advanced, the way they got it in is. And honestly, bringing light to this is the good part. Because let's face it, most OSs these days have good protection. The only "vulnerability" is probably the organization and/or the humans in the gears.

They can run just string reversion, for example taking some strings from the end of file and putting it to the start of file, so you cant open it, and mention that it's strongly encrypted. ive got a ransom like that once. Its time saving, when you need to corrupt large amount of data, before ransom to be found

Nice! I look forward to seeing more security related content on your channel! Thank you for supporting our community! 🧠🏴‍☠

The large fonts are great. This is the first malware video I've ever seen. I'm very glad that you're a white hat guy! Keep up the good work.

love this type of content !

Hey, cybersec engineer student here poking around with reverse engineering. Love the quality of the content! I'd love to try and apply my knowledge on some malware reversing. Is there any (softly) obfuscated malware that you would recommend to play with?

Thanks for putting up with the large font, certainly was appreciated. Cheers ~Smile oN

As a cell phone user i love that you made the font larger 🙃 i appreciate your thoughtfulness

They don't care if you have the encryption/decryption algorithm since it doesn't do much good without the private key. It seems unlikely they're "mad at you". Still, an interesting video.

Was the "encrypt" command really malware though? It looks like a useful cli tool for legitimate purposes, and maybe it's open source software that they pulled off someone's github - in which case they wouldn't care if someone gets into the source code.

Thank you for the big fonts, makes it more accessible, I have difficulty reading small fonts!❤

Great VLOG. Nicely done. I missed what they did with the private key. Stored it somewhere, or transmitted it back to themselves.? Thanks (I used to work at RSA on their cryptography architecture team.) I wound up in data security consulting.

As someone who's recently been getting into the low-code/JS space due to work, this was very interesting, as you covered the main functions and described what they do, leading to better understanding! Got a subscribe from me.

Love your LL system-related content, could you do one regarding how to use the core dump of a segfaulted C executable? I'd love your explanations on that.

Thank you LLL. Fascinating stuff, can barely follow it ( last time I "played" with code was Dos. LOL. Yeah, old). But its nice to see a pro work.

Thanks LLL! Would love more cyber sec content!

I think, even stripped binary without debug info would have symbol table. Due to external linkage in C/C++ for main function, you'll see it there as it is required for possibility of late symbol resolution (e.g. substituting original main with something else during run-time).

They use rsa_encrypt directly on a blank symmetric key? Did you check the public key for having a low exponent e? If it's 3 or 7 you might just be able to take the 3rd or 7th root of the value to get the symmetric key out.

Very nice work on this. Subbed as well !!

Hay. Thank you for increasing the font size. I appreciate it. ~♡

Thank you triple L! Excited for more rev content! Also binary exploitation and other cyber subjects would be cool

They bought the code. They didn’t write it themselves and must pay a fee to the script writer. The signatures are to ID the program and who must be paid.

Nice analysis! Liked the large font too.

LLL Is the best! Thank you! Just a question, the name of disassembler software that you use is "Ghidra" ?

Good stuff. Still eagerly awaiting part 2 of the baby monitor pen testing too 😉

I haven’t a clue what you just did or either do I understand what you said, but I still appreciate your knowledge, and respect the fact you’re always trying, and most instances succeeding, to be one better than the people who cause so much misery to so many people. Thank you 🙏

Thanks for the readable font size!

If all universities taught like this, we would have a much difficult time getting jobs...

Thank your triple L

Thanks for the big font - nice video, strange that though debug symbols show the variables with strange names...

Thank you triple L. Loving the cyber security content! Keep it coming.. Keep the cybersecurity stuff coming .

If they give you the private key, wouldn't that mean that you could just share it and everyone else will be able to decrypt their files? Also, I think the thing I was most curious about was how they encrypt the file in place. The cryptography stuff seems like they are just using standard stuff, seems unlikely they would mess up there. BTW, wouldn't they want for people to be able to inspect the code at some extent? If you are confident that the code will actually recover your files you're more likely to pay than if you suspect the files may just been overwritten entirely and are now impossible to recover. Leaving debug info may be intentional. There's nothing to hide there anyway, they are doing exactly what you'd expect and the only solution is paying them.

Thank you LLL, as a mobile consumer it’s appreciated

Thanks LLL for the mobile code display. I just subscribed because I have low vision and it helps out a lot when creators go to that lengrh for us.

This was 12 minutes of recommended video, that I watched and said "I'll take your word for it"🤣🤣

Obviously the people making this were just shitty script kiddies. Not only did they not strip their code and left the debug info in it, but you can clearly see that their code is absolute garbage as well. Anytime you have to commit the crime of nesting 5 or 6 "if else" statements you know your code sucks.

As someone who often watches on his phone, I appreciate the effort, but you don't need the font THAT big. If you're watching a programming video in portrait mode on your phone you're doing something wrong. Also, "with debug_info, not stripped" LOL. I'm no infosec/reverse engineering guy, but seeing that in malware is hilarious.

THANK YOU TRIPPLE L! JUst found your channel today I love it I don't even code.

You know what people I commented on a lot of videos about not being able to read them and stuff. This is the first content creators that I ran into that's actually blown it up for the people that have to use the phones that are too poor for the internet. So just content creator on the sign up for that thank you for considering us is part of your viewing group.

Conclusion: Nothing weird or unexpected. On a side-note, if more linux programs were made this way, where they scan for the libs they need and then check each lib to ensure it has what they need, they'd save people a lot of headache with the perpetual fail of libs and their dependencies, and the various versions of them, which often make it difficult to produce an executable that "just works" regardless of the distro.

Why should they strip their code? If it is secure, then this information is useless anyway?

The large font is great for my phone so thanks, but also great for my TV so thanks again. Double thanks for you my good sir!

Thank you L. L. L. The visible size text was quite helpful.

So the only weird thing was the presence of debug symbols? I was expecting _a lot_ more with such a clickbait title. This ended up just being a walkthrough of the most basic steps for how _ordinary_ encryption/decryption works, and barely even that.

they left the debug info to prove that if they give you the private key, you can build a decrypter by yourself, so you know that there is something to buy. quite smart. also if you buy the decript key but you don't have a way to verify or build by yourself the decrypt program, the effort to write a decryptor could be significative and also you may not trust the decrypted data and then make less likely to buy the key. i think that it is really to make you to buy the key, and it is a very smart move.

I have been coding in assembly since the late '70s, working with processors like 8088/86. One effective method to avoid dealing with semi-script kiddie activities is to restrict access to specific files through a tunneling script stored in the RAM. There are various ways to achieve this using concise code snippets. It seems like the world has it backward; instead of preventing such issues with straightforward methods, many rely on extensive, advanced, and expensive antivirus software. What's the point?

Thanks for the large fonts, I am now enjoying your videos from bed before going to sleep 👍

Correct me if I’m wrong (probably am) but the random bytes is the initialisation vector for each chunk? (9:20)

People who got hit by this ESX attack should be fired. The version that was touched by this attack had been release in december 2020 for 7.x and february 2021 for 6.7 ! They were a year late in patching

Thank you SO much! You're a genius!!!

thanks for doing this, very interesting talk. From where I sit I'd be worried about this code could get onto an ESX in the first place. I can imagine how but it makes me cringe :D

The concept of the series is nice but the example is not great. You can tell exactly what the binaries do just from looking at the shell script, and it doesn't really help to have debug symbols etc because what you really need is the private key. They pretty much could have done the same thing using readily available cli tools. It would be nice if you could show examples where reverse engineering lets you fix the damage because they have done something stupid like embedded the key in the binary etc, but I don't know how easy it is to find examples of that kind of thing.

why should the attacker care if you reverse engineer their binary? 2:47 - They don't want you to find the vulnerability that gave them exec permission on the host. And they don't want the channel used for money transfer to lead to their identity. That's all. - Antivirus people will find a way to fingerprint the binary regardless of it being stripped or reverse engineered or what not. - If the data is "properly" encrypted, it doesn't matter that you know the alg - without the key you cannot do anything anyway.

This was really interesting. I'd love to see more content like this.

you went from an informative, straight to the point, understandable and good title (iirc it was "I reverse engineered this malware" or something) and then changed it to "I HACKED THIS MALWARE OMG"

I would love to see death penalty for those who write ransomware and malware.

Thanks for the large font size 🙏

Another here who likes the large font. I watch via casting to my TV and it made everything nice and easy to read. No squinting required. Thanks!

Ok, I didn't expect a simple open bash script doing a lot of it. Possibly explains why there was a lot of seemingly rookie moves in the encryption code. I suppose it does what it needs to do to accomplish what they're trying to get done. It will be enough to get a result from most people and businesses.

Thank you LLL, my eyes appreciate it.

Make a series of these 💯

Thank you, LLL. I appreciate the large code font! It doesn't looks cursed as a video.

I'm all microcontroller firmware, but I've been very interested in higher level info sec for a long time.... been listening to old stuff like Security Now for a decade. Definitely love this content.

I'm on the toilet with my phone on hand really appreciating the fontsize. Thank you Mr. Triple L

Thanks for the larger font size!

Thank you for the 64 size’s font 🙏🏻

Thanks for the font size!

props to you for including mobile/partially blind accessibility

I'm just smart enough to hear you speak and know that I'm not smart enough to understand 90% of what you said. Whatever you're doing, keep it up

Thank you LLL for the large font

I'm rarely watching your Videos on my phone, but this time I was, thanks :)

Thankyou for font size!

The .pem file in the encrypt argument list gave everything away, even without the debug info.

Thanks for making the font bigger

Hey Lx3, thanks for enlarging the text so I can see it on my phone. Not that I have any idea what any of it means, it's just nice to know that you're thinking about your audience. Good form, brotha. Bravo.

Thank you, awesome font size

As someone that binges these during downtime while not at my pc I appreciated the larger font

Thank you for the huge font, my laptop is upstairs.

Well they are certainly going with the No Security Through Obscurity Principle.