The two former classsmates of Malik's at Bahauddin Zakariya University in the city of Multan said she regularly attended Al Huda classes, whose stated objective is to bring women "back to their religious roots."
"She used to go to attend sessions in Al Huda almost every day," said one of the former classmates, who spoke on condition she not be identified. "She was not too close to any class fellow."
The former classmate said that Malik, who studied pharmacology at the university, did not share her thoughts on religious issues.
"We all are in state of shock," this person said.
Experts said that the majority of women who attend Al Huda institutes, located in large cities, wear the hijab. They are usually from affluent families, as Malik was.
Dr. Ayesha Siddiqa, a Pakistani security analyst, said Al Huda teaches women "fundamentalist" ideas, though it does not necessarily promote a jihadist agenda.
"I call Al Huda the fourth generation of religious seminaries. It does not promote use of violence but takes you closer to the red line," she said. "Now, it is a personal decision to cross the red line and take or give one's life."
Siddiqa said that the impact of the institutes is widespread, because a child who attends can influence other members of her family. "People would be familiar with, for instance, a daughter going to an Al Huda changing the mother and eventually the entire household. This dynamic is mirrored in more traditional seminaries as well."
Malik, 29, was born in Pakistan to a land-owning, politically influential family in Karor Lal Esan, in southern Punjab province. Though Malik's family moved to Saudi Arabia when she was a child, she returned to Punjab to study pharmacology at Bahauddin Zakariya University from 2007 to 2012.
One of her professors, Dr. Nisar Hussain, recalled her as "a very hardworking and submissive student," and "an obedient girl." He said she came to school veiled.
"She was religious, but a very normal person as well," Hussain said in an interview. "I cannot even imagine she could murder people."
A family member in Pakistan who asked not to be identified said that she had been a "modern girl" who changed during college.
After university, Malik returned to Saudi Arabia. In the last few years, she entered into a relationship with Syed Rizwan Farook, a Southern Californian of Pakistani descent who she met online.
Last year, Farook brought her to the United States on a K-1 visa, also known as a "fiancee visa." The couple lived quietly in a rented two-story townhouse in Redlands with their baby.
Last Wednesday morning, the couple opened fire with assault rifles on a holiday gathering of Farook's coworkers from the San Bernardino County Department of Public Health, killing 14 people. Authorities said that shortly before the massacre, Malik pledged fealty to Islamic State in a Facebook post. She and her husband died several hours later in a shootout with police.
Sadaf Ahmad, an assistant professor at the Lahore University of Management Sciences, has written that Al Huda founder Farhat Hashmi's denunciation of various cultural practices and disapproval of Westerners and Indians gives women a new conception of their identity as Muslims.
Ahmad found Al Huda graduates "very intolerant and judgmental toward people who were different from them."