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Ask HN: What's your proudest hack?
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Re: Ask HN: What's your proudest hack?
#52I once wrote a keygen for AI War, an indie RTS game by Arcen Games. The game was written in C#, so I decompiled it and found the function that checked the keys. It used some kind of PRNG, maybe a Mersenne twister, but customized a bit. Rather than reverse engineer the whole thing, I loaded the "buildKeyFromPrefix" function right out of the exe (like it was a DLL), then built a WinForms wrapper that would show a valid key for each of the expansions. It used a predictable incrementing integer ID for each expansion, so I even included a few future ones.
I never shared this beyond my personal friend group. We went on to play (cumulatively) probably two thousand hours of AI War using this crack. Once I got out of college and got some income, I bought 4 copies to make up for it. Sorry Arcen!
Re: Ask HN: What's your proudest hack?
#53I worked for a healthcare startup that interfaced with a lot of large insurance companies. They had no API access for their patient information and would just give us credentials to ancient web portals instead. I wrote my own browser automation scripts to create our own internal patient API. Ended up reducing claim billing errors by a ton and resulted in 6 figures a month in additional revenue.
What impact did the 6 figures in additional revenue bring to you personally vs. the owners of your startup? How were you acknowledged or compensated for this feat?
Honestly I was a brand new hire and it was my first real engineering job so I gained nothing from it. At the time I had no idea how to advocate for myself or my accomplishments. Big lesson learned.
Re: Ask HN: What's your proudest hack?
#54Not that hacky or mind-boggling, but does involve a hex editor and lots of money... I added support for the '\ ' PostScript escaped space sequence to a custom, high-performance PDF parser. A former employer used this to derive key figures from financial statements. Any change to the parser had to be Pareto-optimal: so if you modified the parser, it should not fail to parse any key figure that was previously possible…
"to build a custom, high-performance PDF parser" ?
Re: Ask HN: What's your proudest hack?
#55We needed to take delivery data from a proprietory legacy system. It already printed delivery notes so I spliced into the RS232 cable to the printer and took a feed into a second PC.
I then wrote a quick and dirty comms program to suck the data in, discard the unwanted control codes etc, and scrape the data into a usable form.
This was in pre-windows days, so the data going to a dot matrix printer was pretty simple. It would be a lot more chewy now I suspect.
Re: Ask HN: What's your proudest hack?
#56Not code. But I bought an ATM once, set the surcharge to something like $10, then opened some checking accounts with "free ATM rebates", then just started making withdrawals like crazy. In case it's not obvious, the cash just goes in a circle and the ATM surcharge shows up as profit for the ATM owning entity (the expense of the surcharge fee is refunded by the bank, so no cost to that entity). Banks assume these are…
Was not expecting confessions here!
Re: Ask HN: What's your proudest hack?
#57Tribes 2 had in-game scripting. You could open a console and enter commands or run script files. I was young and just beginning to learn programming.
I noticed that if you malformed a certain command, a mere syntax error, it would crash the game clients of everyone else you were in a chat room with (the game had in-game chatrooms). I was apparently one of the few who knew this because the game didn't immediately become a crash fest as it would have if word had spread.
There was a game mode where players would begin the game frozen with the clock stopped. This allowed serious games to be organized where all players were ready before the match began. I found a command that allowed me to unfreeze my character, and I could move about while everyone else was frozen.
There was a debug command that would dump the location of all players and deployable items. I wrote a script to dump this data, parse it, and update my hud with the data, several times per second. This was cheating, but it did serve as one of of my first experiences with programming. It was a hack I made myself and did not share, although I know others were aware of this cheating technique. This was later in patched out of the game.
Re: Ask HN: What's your proudest hack?
#58My worst hack was a bug in a small network I wrote to interface to some barcode readers and displays. There was a buffer overflow in the interrupt routine of my 8088 assembler code, which would occasionally miss an outgoing character.
The prompt should have read "Please scan card count", but unfortunately it missed the "o" out of the last word...
Re: Ask HN: What's your proudest hack?
#59Not code. But I bought an ATM once, set the surcharge to something like $10, then opened some checking accounts with "free ATM rebates", then just started making withdrawals like crazy. In case it's not obvious, the cash just goes in a circle and the ATM surcharge shows up as profit for the ATM owning entity (the expense of the surcharge fee is refunded by the bank, so no cost to that entity). Banks assume these are…
Was not expecting confessions here!
Lol yeah it definitely felt shady. My attorney said it was legal but they could probably bankrupt me with legal fees if they wanted to. I thought of it the same as any type of reward people like to find ways to take advantage of (miles, cash back, etc) and I just found a loophole that was pretty high friction so kind of off the radar (friction = I had to buy an ATM!).
Re: Ask HN: What's your proudest hack?
#60Earlier quoted context omitted.
Was not expecting confessions here!
Lol yeah it definitely felt shady. My attorney said it was legal but they could probably bankrupt me with legal fees if they wanted to. I thought of it the same as any type of reward people like to find ways to take advantage of (miles, cash back, etc) and I just found a loophole that was pretty high friction so kind of off the radar (friction = I had to buy an ATM!).
Did you just cycle the money in the machine, or did the cycle somehow involve taking a bunch of cash, depositing it in your checkings account, getting new cache delivered by courier, put it through the money machine, repeat...
or a tighter loop I can't grasp how it would work with your account?