solved using https://stylesuxx.github.io/steganography/
Output:
Well done, you managed to use the classic LSB method. Now you know that there's nothing in the sea this fish would fear. Other fish run from bigger things. That's their instinct. But this fish doesn't run from anything. He doesn't fear. Here is your flag: shkCTF{Y0u_foUnD_m3_thr0ugH_LSB_6a5e99dfacf793e27a} ...