Advent of Cyber 2023 Day 5 Reverse Engineering Simply Cyber

In this video I'm walking through Advent of Cyber 2023 Day 5, a DOScovery.
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[@simirock]

on "22.00" people on Macbook Touch bar should press fn button then choose f10 on touch bar to move around complie folder and File, Edit etc.

[@SimplyCyber]

Solid tip!

[@crispawlitz]

This was driving me nuts. Thank You!

[@cytechlux]

OMG Thank you. i have the M1 ( not touchbar) and option+C wasnt working !!! this worked perfectly back to figuring this out myself

[@SimplyCyber]

going to have to pin this comment. seems like helping a lot of ppl @@crispawlitz

[@SimplyCyber]

Gotta pin this. helping a lot of ppl. thx for sharing

[@natalieohaneje]

Enjoyed every bit of this. Your enthusiastic approach made learning so much better. Thank you for this!

[@SimplyCyber]

thank you. so much fun to make content like this.

[@abhithesh2465]

for the people wondering ,pipe( | ) is kind of a connector used to join 2 different commands ,or to give the output of 1 command to the next command joined by |

[@stou-hh6yh]

Yeah but coul'nt type it, neither by alt +6 nore with shift and backslash; but eventually did more of type

[@pursuitofblyss]

Looking forward to getting started on everything, hopefully today but at the latest tomorrow. 🎉😃

[@UnixGuy]

Nice work!

[@SimplyCyber]

Thx! We’re still due for a collab! 💙

[@UnixGuy]

looking forward to it :) @@SimplyCyber

[@aminamusa6346]

Great Teacher. So far you are my favorite.

[@SimplyCyber]

Thanks!

[@AbyssalCurse]

I've done all of them up until now and so far you are my favorite creator to follow along with. I'll Definitely checking your other stuff out!

[@SimplyCyber]

Thx. Join us for the morning briefs livestream, I think you’d love it. SimplyCyber.io/streams

[@kimberlycanfixit]

Hey hey hey! Great video! Thanks for sharing more about reverse engineering with us today on AOC!

[@SimplyCyber]

Any time! Glad you enjoyed kicking it old skool!

[@TheVio888]

I just completed this task and I must say, my favorite Advent Cyber 2023 Instructor! With your enthusiasm and eloquence, made it so much fun to complete this task. Thank you!

[@SimplyCyber]

Wow, thanks! I love doing them and hope thm asks me back next year

[@camilovasquez8530]

Thank you so much for your great presentation, most appreciated and good learning! :)

[@SimplyCyber]

You're very welcome!☺️

[@swiftrouge3231]

Loved this task! As well as the pace of learning and going thought the task was perfect for me as well as the addental nuggets of knowledge! Thank you!

[@SimplyCyber]

My pleasure. Glad you enjoyed

[@coffeebreak4888]

Thanks for doing this for us.

[@CyberReddie]

Thank you for the challenge and the detailed explanations!

[@SimplyCyber]

My pleasure!

[@emmanuelchatain4397]

merci c'est magique !

[@johnnie5836]

Great video Gerry, the story read was epic!

[@SimplyCyber]

I HAD to do a dramatic reading! 😊

[@Toasty-pops]

Great presentation! Love the throwback to old school DOS days. First PC I used was a Tandy TRS-80 😅

[@SimplyCyber]

Classic

[@Lets-Bike-EAT]

Best presenter so far! Thank you sir!

[@SimplyCyber]

Appreciated!

[@romanx71]

Thank you. Great video. Day 5 done.

[@SimplyCyber]

Thank you! 💙

[@kingyoutube156]

Thank you!!!

[@SimplyCyber]

yw

[@rokkr]

#TeamReplay watching the Daily for today, followed by the THM box. Today is a good day ❤

[@SimplyCyber]

enjoy! it was a fun one.

[@_.sSiL9]

What a nice experience, thank you !!👍

[@SimplyCyber]

Glad you enjoyed it

[@wolfrevokcats7890]

Superb high quality video with good explanation. Thank you!!! I looked at your channel and found that this is the only video about Advent of Cyber 2023, or I might overlooked it. If there are others, please let me know. Thank you again

[@SimplyCyber]

I hosted day 5 officially w TryHackMe. I would have enjoyed doing all the days but can’t due to time. Thx for kind words though!

[@playfulsteps9249]

Thanks for all the enthusiasm and great tips! I was great to touch DOS again; it reminded me of when I would mess around on Windows 3.1 before loading hard disks via the A: drive.. lol .. Cheers!

[@SimplyCyber]

Omg the A: drive. I forgot about that. The “scraping” sound of the metal slide. Nostalgia

[@playfulsteps9249]

@@SimplyCyber 😂😂😅 omg, the sound lol

[@mattmcdaniel727]

Best TryHackMe day ever. Thanks Gerry for today's AOC

[@SimplyCyber]

thanks so much Matt. Great to see you in the comments.

[@MISTYEYED.]

#teamreplay

[@Ryalus]

Tis was great, never thought I'd be looking at DOS in an advent of cyber.

[@SimplyCyber]

Nostalgia vibes for me. So fun to come full circle

[@kermel77]

Thanks a lot :)

[@SimplyCyber]

You're welcome!

[@cipher3966]

Glad I am not the only one here learned this on their first computers

[@SimplyCyber]

lol. i got mad nostalgia vibes.

[@Zetoskeris]

Way to read that story Gerry!

[@SimplyCyber]

if you're going to be a bear, be a Grizzly. lol

[@navnistuff]

#preach Wow blast from the past. Yup, the times of turbo buttons and switching of floppy disks for installing software, that off course fail on the last ones

[@SimplyCyber]

Screaming 33Mhz

[@mrashco]

Awesome video! I'm not an RE guy, so this was a nice intro!

[@SimplyCyber]

Awesome, thank you!

[@doctorc-ton1099]

My first IBM compatible PC featured the i286 CPU starting with DOS 3.31 and I upgraded to DOS 5 on that old PC. I left it there because DOS 6.22 used a little more of the 640K RAM than DOS 5's footprint. I managed to use some of the 384K that was called "upper memory" that the machine actually had, and I could load device drivers into that RAM space. Yup, 1 MB RAM was it! That machine was my everything for so long, and got a second life when I installed the so-called "Make-it-486" Texas Instruments mod chip. It actually did upgrade it to a 32-bit CPU, added an FPU to the process, and I was doing more than ever before! It could play those vintage Sierrra and Microprose games better, and even play Wolfenstien 3D! I am not sure if it played the old Commander Keen games, or old Duke Nukem 2D side scrollers....hard to recall. Of all the retro computers I had, this one was loved. It broke only three times! Once by my hand frying the motherboard with some weird static electricity incident, long story, and was fixed under warranty, and the other was that the PSU broke, and got a newer quieter one installed. The third was when the Dallas Clock failed. I found an identical chip on this huge old modem, and pulled it, added it to my old PC, and it booted up beautifully one again. It's 2023 and the machine still can power on, boots to DOS, with my custom C prompt that shows you the current date and time every time you hit the enter key. Is this PC still useful? Maybe...I can copy 5.25" to 3.5" floppy or use a special tool i found that can duplicate any floppy perfectly. It can still play those aforementioned games, but with such a tiny hard disk, only the Wolf3D and Spear of Destiny are loaded. The other thing I did which i thought extended my machine a bit was the use of "Stacker Technologies : Stacker" disk compression. I told it to use a 15 MB file as a "D:\" drive which allegedly thinks it's 30 MB. Of course, that's not true, seeing that certain file types do not compress at 2:1 ratios exactly, but I'll tell you what, that's where some of my shite is, and I actually put the bulk of my DOS OS in that volume with the essentials in the C:\ drive. With a special Boot disk I made, i could change the CONFIG.SYS and made the leanest DOS environment memory footprint to play those games that needed all that precious RAM. The last impressive thing i was doing with that computer (besides learning QuickBASIC, playing with Microsoft Paint for DOS, and trying to play with Windows 3.1 which left so little RAM, it could just play Solitaire).... The last thing that I was doing with this PC was using this application called "Vivid Raytrace". It was painfully slow to render an image on that machine! What an impressive thing though! It would create 32-bit native images that I needed a DOS image file converter to create an 8-bit JPG, and then use that same application called "Display" to view the file. Though when I found out that the program can view the images native to my VGA screen, they looked so cool! To make a scene with Vivid, you had to write code! So theoretically, and actually, I would create a program with Quickbasic to do some mathematical plotting, and batch the codes needed to render the scene. Beautiful! DOS was the foundation for what I did on computers. DOS was great since it had help included in the files. The disk operations were logical. There were some really good DOS shells that were truly useful. I had "PC-TOOLS PC SHELL" and one of the text based versions before it switched to graphical was FAST loading. It did everything you needed to do, and my favorite thing to do was view file contents. Even if the output was hex, I could switch to ASCII and every file might have some text in it to read. I thought there were secrets in there! I was able to understand file patterns and I didn't even realize the "magic bytes" were those first 2, but I did already know that they were significant, since each file had unique first 2 bytes because I looked at so many file types, there was something about them. All of this before there was an internet to log into! The next computer was a Win95/98 PC, and that thing did a lot, but was a nemesis computer....that story is for later. Hey, thanks for reading, and doing this blast from the past. I felt pretty proficient in this task. I learned an interesting anti-easter egg though: 1. My mouse worked fine in the MS EDIT program, like it did in those old days. 2. I figured out that it would be easy to just use EDIT to read and fix the BAK file before reading the rest of the syllabus, and i decided to "save as" a different file name, and when i used the task's bumaster.exe to use that new file i made, it didn't work! This leads me to believe that it was hard coded to accept that one and only filename in order to spit out the Flag.

[@SimplyCyber]

Wow. What a post and fun to read. Agree on hardcoded solutions. Your post takes me back nostalgia. I remember being the “cool” kid that got the 14.4 upgrade for my 2400 and I was screaming fast on BBS. Also my first machine was 486sx 25 w/ a 33Mhz turbo button. Sierra games!!! Now that’s a blast from the past. All the best and thanks for playing.

[@famuellersman]

#Preach

[@mattmcdaniel727]

WOOOOOOH #First

[@richardcall2994]

#preach

[@ravbhuva]

I like the way you point things out and zoom in. What software is it @gerald

[@SimplyCyber]

SySinternals ZoomIt

[@abdulo8963]

Hi Dr Gerald, I can't find your full GRC course playlist on KZbin. Was it removed? Thanks

[@SimplyCyber]

My course is not available on KZbin. It is here: simplycyber.teachable.com

[@abdulo8963]

​@@SimplyCyberThanks

[@mytube7473]

Love that you put energy into reading the story. Thanks.

[@SimplyCyber]

my pleasure. it was a lot of fun.

[@raymondcruzrc]

GOAT

[@SimplyCyber]

So kind. 🙏

[@davidsekanic7636]

#Preach Windows 3.1 & DOS 6.0

[@SimplyCyber]

Old skool

[@s0ursand]

anybody else having problems with the compile menu ? I keep doing alt+c but nothing happens edit: nvm, by pressing F10 (on Windows) you can access the menu with the arrow keys

[@WalterDeRooij]

3.11? you go youngun'

[@hjaldrgegnir]

I can't even seem to type a "backslash" in DOS...so frustratingly annoying. Great video though, as always Gerald :)

[@FabianRMercenary]

had the same problem (german keyboard layout) - AltGr didn't work for me but CTRL+ALT+? (\-Button) did it

[@hjaldrgegnir]

@@FabianRMercenary Thanks for the tip, buddy!

[@SimplyCyber]

Thx for the assist!

[@muzan...5368]

Thanks buddy @@FabianRMercenary

[@andry_neuropsy]

YOU JUST SAVED MY CYBER-LIFE ! Thank you so much ! ahah@@FabianRMercenary

[@beyzabarn481]

I spend a lot of time but I can't use \ ,| and can't see flag please help me

[@ItsMePhoebe]

Same, I'm using a non-us keyboard, it's so frustrating- lucky it was available in this video though!

[@justanoob111]

lol "kickin it wicked old school" You're the man

[@SimplyCyber]

Thx man! I had fun w it

[@shaneyb_80]

#preech

[@jamesdriscoll1658]

#teamreplay. I remember Windows 3.1.1 and D O S

[@SimplyCyber]

Classics!

[@tR0YYYCTF]

when i click start machine i see a white screen any help please

[@SimplyCyber]

I’d try restarting browser. Maybe clear cache or try different browser

[@kimberlycanfixit]

We need a “you do you, boo” emote or sound clip

[@SimplyCyber]

😂

[@marciorodrigues3584]

Anyone else went first to check the game directory and see what retro games they have there?

[@SimplyCyber]

lol!!! Hidden Zork would have been next level

[@marciorodrigues3584]

YES! Zork was so much fun! I remember playing Doom and Prince of Persia aswell. Oh the nostalgia!@@SimplyCyber

[@nickhanks3591]

dude bro he does not look very old

[@SimplyCyber]

Thank you!!! I’ll take it!

[@intrnlstranger4646]

I skipped most of the videos so far, but couldn't pass yours, Gerry

[@samihakonen8193]

Can't be done with MBP with FI/SWE keyboard... This was just poorly designed and executed challenge. There is absolutely no way to make e.g. ":" with this keyboard :(

[@i_am_dumb1070]

DONE

[@SimplyCyber]

great work!

[@Rhonda_Rummerfield]

#preach

[@SimplyCyber]

vibes. :)

[@user-bj5qd6ky8h]

#teamreplay