The 17-year-old was attacked in the village of Hale Barns, Cheshire, at around 6.40pm on Saturday night. He was taken to hospital where he died a short time later.
His devastated family said Yousef's death was "every parent’s worst nightmare".
In a statement released by Greater Manchester Police, the family said: “Yousef was a loving and caring son and brother and he meant the world to his family.
“He was a sporty young man, a dedicated student and so bright. He had everything to look forward to.
“We are absolutely devastated and cannot believe that our son has gone. This senseless loss has affected the whole community.
“Yousef had only phoned home hours earlier to say that he would be home for his tea, but the next knock at the door were officers with the tragic news, it is every parent’s worst nightmare.
“We would appeal to anyone with information to contact the police and to help us find out what has happened on Saturday evening.
“Only recently had we talked about his promising life ahead of him and how he was looking forward to life. He was a promising student and loved by everyone.”
Yousef, who was from Burnage in Manchester, dreamed of becoming a heart surgeon.
He is thought to have won a scholarship to attend the £12,000 a year independent Manchester Grammar School.
His death came a day after another teenager, , was fatally stabbed in a London park prompting heightened calls for the government to take action on violent youth crime, which has spiked by 93% in England in recent years.
Leading the investigation into Yousef's death, Detective Chief Inspector Colin Larkin, said: “The last couple of days have been absolutely devastating for Yousef’s family – something no mother or father should ever have to live through.
“Our specialist officers have been supporting them as we continue our investigation but now I turn to the community for their help."
Two 17-year-old boys were arrested after the stabbing of Yousef on Saturday evening.
The two teenagers remain in custody with police granted an extra 24 hours to question them.