A keylogger for macOS.
I wrote this keylogger to analyze which keys are pressed the most. Below you'll find instructions on how to run the code and analyze the data.
Note: This keylogger will capture all keyboard input, including passwords and other sensitive information. Make sure to stop the keylogger before entering such data.
Keys are logged in CSV format to stdout. The first column is the key pressed. The second column is the modifier that was held while pressing the key:
UP_ARROW,
DOWN_ARROW,
a,
t,
ESC,
s,control shift
s,alt
ESC,
[,control shift
c,control
For example c,control means that Ctrl+C was pressed. If no modified was pressed, the second column is empty (a,).
To find out which keys have been pressed the most we can load the generated CSV file into visidata.
visidata keylog.csv
Then press Shift+F to get the histogram:
The repo comes with a Python script that can parse the generated csv file and format the output for the keyboard layout analyzer. KLA will give you recommendations about the best keyboard layout based on how much finger moved and other factors. It can also generate a heatmap:
Run the Python script and copy the output to your clipboard:
python3 kla_text_input.py keylog.csv | pbcopy
Then go to keyboard layout analyzer and paste the text into the textbox and click "See which layout is the best".
The keyboard analyzer runs in client-side javascript, however to be sure that no senvitive information is leaked I recommend to disable your internet connection before submitting the text, or run it locally. Instructions can be found in the github repo.
Note that the keyboard layout analyzer doesn't support virtual keys such as Shift/Cmd/Ctrl/Delete/Arrow-keys so they are excluded from the statistics.
Since this is a keylogger it doesn't come with a pre-compiled binary.
You can compile it with:
clang -o keylogger keylogger.m -framework Cocoa -framework Carbon
Next we need to allow the keylogger to capture keyboard input. To do this we have to open System Preferences -> Security and Privacy -> Accessibility and add the keylogger binary to the list. Also make sure that your terminal app is in that list and allowed to capture input:
To print the logged keys to stdout run:
./keylogger
If you see an error ERROR: failed to create event tap then you need to allow your computer to capture keyboard input (see Installation above).
If you want to output the contents to a file:
echo "key,mod" > keylog.csv
./keylogger >> keylog.csv
Code is taken from sniffMK and NESEmulator.