We are given an URL, and the challenge says that the URL contains “the entire internet”. If we try to download it we will see that the file is unreasonably large (hundreds of terabytes) and that there is no way we could wait for long enough to get to the end.

We can make use of HTTP Range headers, which are normally used to resume downloads from a client-specified point. For example, if we send a request that includes a header Range: bytes=1000-, we will get the contents of the file starting at byte 1000.

The easiest way to do this is using a curl command. Since the server returns binary data, we will pipe the output of curl through xxd to convert it to a format we can output to the terminal:

curl -H 'Range: bytes=199999999999000-' | xxd

At the end of the output, we can see the flag for this challenge.