So you are talking about Exploit hack? The Exploit ability adds an QTE bar while you are hacking, right below the hacking percentage display. Hit RB again while the bar is in green area, hack will succeed instantly, (before timer finishes)

After numerous tries I did figure it out. In the tutorial, it would be much easier if the moving green exploit block was larger, you could then guess that you need to match the green moving block to the white block under the main progress bar.

I'd suggest that some text could be added to each tutorial to explain it.

"To activate the exploit, you need to match the lower green block to the white block under the main progress bar. "

I'm not sure how the virus infection of connected Genies is supposed to work too (another skill you unlock). I think infecting one of the connected Genies does something to the other connected genie that's just my guess. I think it could use an explanation too.