First, we'd see this. Highly capable hacking AI with vast resources performing attacks against standard computing platforms that overwhelm human operators.
Second, human operators deploy capable adaptive protection AI to fend off AI attacks in realtime.
Then, the attacking AI partially switches from attacking programs to attacking protective AI.
The situation devolves to an arms race of tit-for-tat. You start seeing some protection AI running counter attacks against the attacking AI.
The escalations continue in complexity and speed to the point that almost all humans are left in the point of "wtf is going on".
[1] https://store.steampowered.com/app/731040/The_Invincible/
The second problem -- already seen in Ukraine v. Russia -- is that in a high-stakes situation, humans will take every safeguard off.
Humans are paper clips long before that.