Known Ciphertext attack on a software implementation

Hello,

I have a question regarding doing a known ciphertext attack on AES-ECB in software.
I initially based myself on the tutorial PA_HW_CW305 that does this attack on a hardware implementation using the last_round_state_diff model.
Doing this attack in software does not work, I assume since the HW register it tries to attack is not present in a software implementation.
So I was wondering if it is possible to perform a known ciphertext attack against software and if so how this is usually done.

Thanks in advance!

Kind regards
Brent