It is not a multi attack. It is a chance at multiple damage from one attack, one animation similar to Rey Flurry of blows. You will see multi damage numbers as show below
Fotp multi attack single damage.
Boba multi damage single attack.
Rey multi damage single attack.
Boba is worded just like Rey.
There is a possible bug with it triggering multi counter attacks.
From the post below counters were changed specifically vs Rey multi damage single attack. Counters are supposed to trigger on the number of attacks dealing damage not the number of times damage is dealt.
https://forums.galaxy-of-heroes.starwars.ea.com/discussion/comment/202837/#Comment_202837
From @CG_Method
The multi-counter was unintended to begin with, an unfortunate result of Counter Attacks being determined per damage effect, rather than per attack. Thankfully, there's an override for that, so only the first hit can trigger Counter Attacks now. Considering that you still only need to succeed a single Evasion check to avoid all the hits, it only seemed fair that you only got one Counter, too.
