Related: My grad school had a shared bin/ directory with common local tools. Of course, that directory was after /bin and /usr/bin in the PATH so that no one could override “ls” or “more”. So… one grad student added scripts with names that matched common typos: “sl” and “mroe”!

Sure enough, they got run. The scripts didn’t take over your account. They ran “ls” and “more”. They may have also logged your username in a file so he could lord it over you.