CyberDefender - GrabThePhisher

CyberDefender - GrabThePhisher

Challenge: https://cyberdefenders.org/blueteam-ctf-challenges/95

:::spoiler TOC [TOC] :::

Scenario

An attacker compromised a server and impersonated https://pancakeswap.finance/, a decentralized exchange native to BNB Chain, to host a phishing kit at https://apankewk.soup.xyz/mainpage.php. The attacker set it as an open directory with the file name “pankewk.zip”.

Provided the phishing kit, you as a soc analyst are requested to analyze it and do your threat intel homework.

==Q1==

Which wallet is used for asking the seed phrase?

Recon

從scenario就可以知道他大概是一個網站被攻擊後盜用,轉變成用來騙別人的釣魚網站,因此可以看一下整體的資料夾結構會發現他所採用的錢包就是metamask

:::spoiler Flag Flag: Metamask :::

==Q2==

What is the file name that has the code for the phishing kit?

Recon

同上,只要觀察資料夾結構就可以知道有一個file叫做metamask.php

:::spoiler Flag Flag: metamask.php :::

==Q3==

In which language was the kit written?

Recon

同上

:::spoiler Flag Flag: php :::

==Q4==

What service does the kit use to retrieve the victim’s machine information?

Recon

這個就比較有趣一點,通常問的應該是哪一個api之類的服務,所以應該要往這個方向想,看了一下matamask.php,裡面有提到

1
$request = file_get_contents("http://api.sypexgeo.net/json/".$_SERVER['REMOTE_ADDR']); 

代表他所使用的應該是Sypex Geo這個service,查了一下,可以看一下github repo,的確就像題目敘述一樣是可以藉由IP取得受害者機器的一些相關訊息

:::spoiler Flag Flag: Sypex Geo :::

==Q5==

How many seed phrases were already collected?

Recon

我是直接看/log/log.txt的內容發現有三行,且每一行都有固定12個phrase,所以我猜應該已經取得三個受害電腦的seed phrase

:::spoiler Flag Flag: 3 :::

==Q6==

Write down the seed phrase of the most recent phishing incident?

Exploit

同上,把最後一列的seed phrase貼上就對了

:::spoiler Flag Flag: father also recycle embody balance concert mechanic believe owner pair muffin hockey :::

==Q7==

Which medium had been used for credential dumping?

Recon

如果仔細看metamask.php的後半段會發現他還有call到telegram的API,主要用途是拿取seed phrase,再把這些東西append到/log/log.txt

:::spoiler Flag Flag: telegram :::

==Q8==

What is the token for the channel?

Recon

同上

:::spoiler Flag Flag: 5457463144:AAG8t4k7e2ew3tTi0IBShcWbSia0Irvxm10 :::

==Q9==

What is the chat ID of the phisher’s channel?

Exploit

同上

:::spoiler Flag Flag: 5442785564 :::

==Q10==

What are the allies of the phish kit developer?

Exploit

可以從註解當中看到j1j1b1s@m3r0這個人應該也有提供一些協助

:::spoiler Flag Flag: j1j1b1s@m3r0 :::

==Q11==

What is the full name of the Phish Actor?

Exploit

如果把檔案中提供的token/id當作TG的parameter會得到甚麼東西呢?$\to$https://api.telegram.org/bot5457463144:AAG8t4k7e2ew3tTi0IBShcWbSia0Irvxm10/getChat?chat_id=5442785564

:::spoiler Flag Flag: Marcus Aurelius :::

==Q12==

What is the username of the Phish Actor?

Exploit

同上

:::spoiler Flag Flag: pumpkinboii :::

Reference

A walkthrough of CyberDefenders “GrabThePhisher — Threat intel” CTF