The thieves had stolen all but a few dozen of the museum's 1,100 artifacts, leaving behind some statues and painted coffins that were too heavy to cart off. Hanna, a 30-year-old archaeologist, sent out a tweet pleading for help. Soon, she, some colleagues and local police officers were hauling the surviving relics to a truck as men fired automatic weapons nearby.
"We are trying to create communal watchdogs all around Egypt," Hanna said in an interview this week from New York, where she is drawing attention to the looting in her homeland and to the power of social media to help curb it. "But for now we are like butter spread over too much bread."
On Thursday, Hanna will receive an award from Saving Antiquities for Everyone, a New York-based organization that works to protect cultural property. The group praised Hanna for using "social media tools to their fullest potential" to "expedite the recovery of stolen objects, effectively reducing the supply side of the illicit antiquities trade."
On Tuesday she spoke at the Benjamin N Cardozo School of Law at Yeshiva University, and later this week she is scheduled to help lead tours of the Egyptian collections at the Metropolitan Museum of Art and the Brooklyn Museum. She will also deliver a formal lecture Thursday evening at Cooper Union. Her topic is "Saving Ancient Egypt, One Tweet at a Time: How Social Media is Saving One of the World's Oldest Civilizations."
Hanna, who has 29,000 followers on her Twitter account and a growing network of Facebook followers, is also using social media to urge colleagues around the world to be on alert for the looted artifacts. "Egyptian history is being destroyed," she said. "We need a worldwide collective effort."
Then she rattled off site after site - some known to tourists, like Giza and ancient Heliopolis and Memphis, and others that have never been properly excavated - where thieves using bulldozers, dynamite or bare hands have "devoured an archaeological heritage that is 5,000 years old."
Hanna has degrees in Egyptology and chemistry from American University in Cairo and a doctorate from the University of Pisa in Italy. As a grass-roots leader against the pillage that has torn across Egypt since the country's 2011 revolt, she hounds and admonishes public officials, travels to isolated sites to record the damage, faces threats and occasional gunfire from organized looting squads and appeals to younger Egyptians to embrace their land's fabled heritage rather than ransack temples and graves for fast money.
For decades, she said, average Egyptians "believed the heritage belonged to the state, to tourists, not to the people." As a result, she said, youth are easily persuaded by their elders to help plunder cemeteries and religious sites in a fashion that recalls the thievery in Dickens' "Oliver Twist."
"There is a big man like Fagin," she said, "who sends these children to go dig and he buys whatever they bring him."
Sometimes the looting is helter-skelter and the sites quickly abandoned, she said. Other times, an area is openly seized by a "land mafia" that methodically uproots tombs, sells off the jewels, linens and fineries they contain, then plows the land to make room for development.
She says such looting and desecration will end only after Egyptians "begin to worry about it very personally." But, she added, "the human tendency toward greed is very strong."
Hanna dropped her postdoctoral work in Berlin in 2011 and returned to Cairo to start the Egypt's Heritage Task Force, a social media network of native and foreign archaeologists, citizens and others to gather information and ideas about Egypt's plight.
Some use online mapping tools to identify looted areas; others hunt through auction catalogs and websites looking for recently stolen objects; and still others assemble groups of activists to converge on besieged ruins to confront the poachers, clean up trash, and generate media attention and official action.
Last summer at Dahshur, a site near the Giza pyramids, where armed tomb raiders were burrowing for treasure, Hanna's tweets about the pillage drew archaeologists and local residents to the site in protest. Those social media efforts, amplified by global news coverage, prompted the government to put soldiers in place for security.
Such confrontations can be dangerous.
"My husband is worried about my personal safety, but I am not worried," she said. "I have put my hands in this can of worms, but, you know, I think I am doing the right thing, and this is enough for me."
In another effort over the last eight months, she has been asking scholars around the world to send any photos they might have of items now missing from the Malawi Museum, which is 190 miles south of Cairo. Thousands of photos have come in, many of which were posted on Hanna's website. The Egyptian government credits the publicity with helping to recover several hundred items.
Sameh Iskander, president of the American Research Center in Egypt and a visiting scholar at New York University, said that because of these kinds of successes Hanna has emerged as one of the most important people in the fight to protect Egyptian antiquities.
"I would say we all appreciate her," he added, "except the looters."