Maria Parsheva, a young Brooklyn woman who stands out among her Baruch College peers with her bright and bubbly personality, was abnormally quiet during her Monday class on Jewish philosophy, her teacher, Rabbi Eric Ertel, said.

News had already spread quickly around the school that Ms. Parsheva had been attacked along with three of her friends after they carried dreidels and a menorah onto a Brooklyn-bound Q train last week.

“You could tell something was wrong,” Mr. Ertel said.

They had been leaving a celebration for the holiday of lights, Chanukah. As another group of young people on the train greeted them with, “Merry Christmas,” one of Ms. Parsheva’s friends reportedly called out, “Happy Chanukah.”

In moments, the group of young people had set upon the Chanukah revelers, leaving them both bruised and shaken. The attack takes its place as the first physical assault among an escalating number of hate crime complaints in the past few months.

A young man on the train came to the rescue, however. According to published reports, Hassan Askari, a practicing Muslim, jumped into the fray to try and protect Ms. Parsheva and her friends — although he ended up suffering bruises himself.

At school on Monday, Rabbi Ertel said friends and strangers who attend school with Ms. Parsheva also reacted quickly.

“The first thing out of people’s mouth was, ‘Is she okay, is she alright?'” he said.

In the end, the Jewish philosophy teacher said he saw a lesson to be learned.

“It’s definitely not a coincidence that it happened over Chanukah, the festival of lights, which happens right when it’s the darkest time of the year,” he said. “This was a dark moment, but at the end of the day you could see some light in it: that the other boy jumped in and helped out. It’s a nice thing to see.”