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