How do bots detect that my private key has a low bit length just by observing my public key when I broadcast a transaction?

Someone has already tried to use it

https://issc.unipune.ac.in/attachments/lasVegas.pdf

https://bitbucket.org/abdullah0096/lasvegas-ecdlp/src/master/

he posted it and then deleted it, but it's still here

00000000000000000000000000000000000000000000000bebb3940cd0fc1491