# Defcamp 2018 Quals: Broken TV


## Description
An experienced hacker gained unauthorised access into a facility with limited options to exfiltrate data but he managed to launch a backdoor to solve this issue. However, he got arrested before intercepting the confidential data. Can you recover the information and maybe do some profits on his behalf? Flag format: `DCTF\{[A-Za-z0-9\-]+\}`
**For this challenge you are allowed to scan using nmap, but it won't help you too much :)**
Target: 104.248.38.191

## Summary
Analyse `ping` time response

## Flag
```
DCTF{EXF1LTRAT3-L1K3-4-PR0-1S-4W3S0M3}
```

## Detailed solution
After pinging the server with `ping 104.248.38.191`, we observe that the response time is in interesting ranges: *under 200*(must be ignored), *greater than 200 and smaller than 1000*(binary 0), *above 1000*(binary 1).
We create some files with pings result and a **Python** [script](solve.py) that analyses and converts them in *binary digits*. Then, we use an [online tool](www.rapidtables.com/convert/number/binary-to-ascii.html), with additional padding and extract some parts of the flag, that helps us to reconstruct the valid flag.