Here is the full list of all 11 Hacknet achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Run ThemeSwitcher
Be granted an account within CSEC
Have a truly absurd number of pointclicker points
Purchase the final PointClicker upgrade
Be granted an account within Entropy
Complete the tutorial earlier than normal
That's just impolite
Complete Bit's final request
Run Clock.exe
Disconnect from a traced system with less than half a second to spare
Master of /el's friendly community