circusmonkey404's Security Site

PicoCTF2018 - Miscellaneous - ACA-Shell-A Objective: It's never a bad idea to brush up on those linux skills or even learn some new ones before you set off on this adventure! Connect with nc 2018shell.picoctf.com 27833. Resolution: OK this one is interactive asmith85338@pico-2018-shell:/$ nc 2018shell.picoctf.com 27833 Sweet! We have gotten access into the system but we aren't root. It's some sort of restricted shell! I can't see what you are typing but I can see your output. I'll be here to help you along. If you need help, type "echo 'Help Me!'" and I'll see what I can do There is not much time left! ~/$  let's start with ls -l to see where we are and whats in there. ~/$ ls -l drwxr-xr-x 2 aca-shell-a_4 aca-shell-a_4 4096 Jul  1  2018 blackmail drwxr-xr-x 2 aca-shell-a_4 aca-shell-a_4 4096 Jul  1  2018 executables drwxrwxr-x 2 aca-shell-a_4 aca-shell-a_4 4096 Apr 13  2018 passwords dr

PicoCTF2018 - Miscellaneous - Net Cat  Objective: Using netcat (nc) will be a necessity throughout your adventure. Can you connect to 2018shell.picoctf.com at port 37721 to get the flag? Solution: This is just a easy way to prove that you know what netcat is or to learn about it if you don't nc 2018shell.picoctf.com 37721 pico-2018-shell:/$ nc 2018shell.picoctf.com 37721 That wasn't so hard was it? That wasn't so hard was it? picoCTF{NEtcat_iS_a_NEcESSiTy_0b4c4174}

PicoCTF2018 - Miscellaneous - Grep Objective: Can you find the flag in file [1] ? This would be really obnoxious to look through by hand, see if you can find a faster way. You can also find the file in /problems/grep-1_3_8d9cff3d178c231ab735dfef3267a1c2 on the shell server. Solution: I just started by cat'ing the file to see what's in it here is a snippet of the result ico-2018-shell:/problems/grep-1_3_8d9cff3d178c231ab735dfef3267a1c2$ cat file                                     8.LK*aVultY,fm+a`r[6($-#EUO>$fL+3!&M&()5oJx*) (9t<u$3WSYH(,e+=+kCi7dG@z!CUSK-lb_UU|Rc3qGw263||PKe%_lkqr(IJ,xuiVrH?=Trq=[Ig <87zmS(xVZ.]o.1E$`R4U/UG#xw<lJ<a+/?8%c@z %<l2os aM(:AOM+GH5eb~<#GAH]9J]GI?BY-o_]#(`!I=;XJV2umPH:/132cf,z`A;]q,8+|1NLp%lQ01z ;pqi]#:XO5Z)ewJSNQg)Os=x6]G1.PXQU=~C    O!$NE&En*:r4b_0s(bfQUb(dm;KgrEP7s.0yCL:/%C$XIC259v0[xBHY(r*;V]@ $f#V115l+R9c.dT5ryL Ohk$|9FC~8K>2NuN7XnsCi3ivET/hQ%o[5SM>pw&Ch<82i+CNQ<@w

PicoCTF2018 -  Miscellaneous -  Resources Objective: We put together a bunch of resources to help you out on our website! If you go over there, you might even find a flag! https://picoctf.com/resources (link [1] ) Solution: This is just a way to have you look at the resource pages picoCTF{xiexie_ni_lai_zheli}

PicoCTF2018 - Miscellaneous - GeneralWarmup3 Objective: If I told you your grade was 0x41 in hexadecimal, what would it be in ASCII? Solution: Once again I just used this chart to see what the Value is for 41 in hex..... A I just got an A picoCTF{A}

picoCTF2018 - Miscellaneous - General Warmup2 Objective: Can you convert the number 27 (base 10) to binary (base 2)? Solution: so just a simple Binary conversion here. If you don't know how to do this google around for Decimal to binary 128   64     32    16   8   4    2   1 0       0        0      0    0   0    0   0 if you switch any one of the zeros in that to a one, you can add the values on top to make the number like 128    64    32    16   8   4   2    1 0        0      1      0     0   0   0    0 would equal 32 128    64   32  16  8  4   2  1 0          0    1     0  0  0   0  1 this would equal 33 so to solve for 27 128     64      32     16   8   4  2   1 0         0        0        1    1   0  1   1 so the answer would be    11011 picoCTF{11011}

PicoCTF2018  - Miscellaneous - General Warm up Objective: What is 0x3D (base 16) in decimal (base 10). Solution: so we just need to convert 3D in I just looked it up in the ascii code table https://ascii.cl/ picoCTF{61}

PicotCTF2018 - Hideout - Scriptme Objectives Can you understand the language and answer the questions to retrieve the flag? Connect to the service with nc 2018shell.picoctf.com 22973 So here are we connect up to the shell and are presented with the following Logic We need to figure out how this logic works, the telnet session has a timeout so manually doing the math here is not possible. So we need to write a script that will figure out the answers ​Rules:                                                                                                                      () + () = ()()                                      => [combine]                                                            ((())) + () = ((())())                              => [absorb-right]                                                       () + ((())) = (()(()))                              => [absorb-left]                                                        (())(()) + () = (())(()())