Double Agents

After a long investigation we have revealed the enemy’s service, which provides their agents with any needed documents. Recent events indicate that there are double agents among us. We need to read the double_agents.txt file in order to identify their names and treat them accordingly. Can you do it? Category: crypto Solver: kh1 Flag: HTB{1v_sh01d_b3_r4nd0m} Writeup When connecting to the server, it sends Welcome, agent! Request a document: When sending something after this, the server interprets it as hexadecimal data and decodes it....

March 24, 2021 · 2 min · kh1

Locked Out

Our domain has been attacked. An APT group has taken over our server and they have locked us out. Our incident response team was able to find some files added on the upload directory but havent been able to extract any information from them. Could you help us login back? Category: crypto Solver: Miroka, HTTP418, kh1 Flag: HTB{15b_4tt4ck5_4r3_c001} Writeup What we got encryption.py - the script used to encrypt the new password leaks - the script’s variables n, rp, and rq new_password - the encrypted new password encryption....

March 24, 2021 · 4 min · miroka, HTTP418, kh1

Missing Pieces

There is serious suspicion that John is a double agent. We found the cipher in his trash can. It looks like he extracted the message and forgot to get rid of the evidence. Can you decrypt the secret message? Category: crypto Solver: kh1 Flag: HTB{m1551ng_v4lu35_m4k3_m3_s1ck} Writeup flag.txt contains a list of 32 lists containing 32 numbers from 0 to 255 each. This is a One-Time-Pad with 32 parts, xoring the lists and interpreting the result as ascii code gives the flag....

March 24, 2021 · 39 min · kh1

Baby Rebellion

The earth has been taken over by cyborgs for a long time. We are a group of humans, called ‘The Rebellion’, fighting for our freedom. Lately, cyborgs have set up a lab where they insert microchips inside humans to track them down. Our team of IT experts has hacked one of the cyborgs' mail servers. There is a suspicious encrypted mail which possibly contains information related to the location of the lab....

2 min · lmarschk

Buggy Time Machine

I am the Doctor and I am in huge trouble. Rumors have it, you are the best time machine engineer in the galaxy. I recently bought a new randomiser for Tardis on Yquantine, but it must be counterfeit. Now every time I want to time travel, I will end up in a random year. Could you help me fix this? I need to find Amy and Rory! Daleks are after us....

4 min · miroka

Cargo Delivery

Chasa, world’s most dangerous gangster, is planning to equip his team with new tools. There is a cargo ship arriving tomorrow morning and the coast guard needs your help to seize the cargo. Our investigators have found the crypto service used by Chasa and his team to communicate for these kind of jobs. Can you decrypt the broadcasted message and identify the container to be seized? Category: Crypto...

5 min · 3mb0, mp455, lmarschk

Weak RSA

A rogue employe managed to steal a file from his work computer, he encrypted the file with RSA before he got apprehended. We only managed to recover the public key, can you help us decrypt this ciphertext? Category: Crypto Solvers: 3mb0, lmarschk, HTTP418, miroka For this challenge, we had a public RSA key with 1026 Bit and a file that was encrypted with the corresponding private key. First approach: manual generate private key We analyzed the given public key with openssl rsa -noout -text -inform PEM -in pubkey....

3 min · 3mb0, lmarschk, HTTP418, miroka