The call comes late at night, waking up a student with an angry voice that issues a threat about the student’s visa status.

Your visa is out of compliance, the aggressive caller says, and instructs the student to send thousands of dollars to an account that he says belongs to “U.S. Immigration and Customs Services.”

When the student says she or he has to call home -- which can be many time zones away for many international students -- the caller warns that if there is any delay, the student will be deported.

The threat is a scam designed to make the unsuspecting student part with his or her money, say school administrators.

“It’s a pretty serious situation,” said Senem Bakar, director of international student and scholar services at American University in Washington.

International students are not familiar “with our police and how things work. And so they sometimes will fall victim to these kinds of calls,” said Masume Assaf, director of international student and scholar advising at Pennsylvania State University.

Scams also come in what look like official -- but cleverly disguised – letters that would make it appear as if the correspondence comes from the U.S. tax agency, the International Revenue Service. These make international students more likely to buy into them.

In one instance a form with the heading, “IRS Form 2623 third-party consent,” tells the individual to complete it with personal banking details, send it back to the IRS for processing, and wait for a refund.

“And it looks pretty legitimate,” Assaf said. But instead, their accounts are hacked.

The legitimate document is Form 2624, or “Consent for Third Party Contact.”

The legitimate immigration agencies include U.S. Citizenship and Immigration Services (CIS) and U.S. Immigration and Customs Enforcement (ICE).

Headlines are full of stories about students who have been scammed. “I was a Chinese grad student and lost all my money to a scam,” wrote Xinlu Liang, a recent graduate of the University of Southern California, for the Los Angeles Times. “How could I have been so gullible?”

Wichita State University in Kansas publishes a page of warnings, alerting students about the scams that include calls to Chinese students from people speaking in Mandarin.

“The caller encourages the victim to fly to China to complete an official statement. They may warn you not to contact any other people including your parents because you are involved in a ‘criminal case’ saying that anyone (friends or family) who is in contact with you may also be in danger,” the web page instructs.

At the same time, the scammer contacts the student’s family members or friends, saying the student has had a car accident or has been kidnapped.

The student has been warned not to contact their family. When their family can’t reach them, they think “something terrible has happened to their child and so they wire money to the scammer to ‘help’ the student with their emergency,” according to Witchita State.

Another way students can get scammed is through eBay and Craigslist, online sites where people buy and sell goods or services.

In some cases, international students who have to shop for housing online arrange to rent a property without seeing it first. When they show up to move in, they find the unit already occupied.

Scammers call from many different phone numbers and use different voices, and fake or temporary numbers that cannot be properly tracked appear on the phone’s Caller ID display. When the number is dialed, the caller hears a message saying the number is out of service.

“There is no grace period. They are very persistent. They are very authoritative,” Bakar said about scammers.

“Caller ID, which used to mean something, means nothing now,” Bakar said.

Assaf elaborates, explaining that scammers disguise their numbers to make it appear as if the police or legitimate agencies are calling. Assaf said she has had this experienced.

“John Smith” called, saying he was from the Montgomery County Police Station. When she realized it was a scam, she pushed back.

But the scammer was confident.

“I said to him, ‘Oh no, I know what you're doing.’ And he said, ‘Look, (...) see the number on your phone?’…‘Look it up.’ (It was) the Montgomery County Police Station” number, she said.

It’s tricky figuring out which calls are real. For some students, this thinking is intuitive. For others, it’s not.

“Some people, you know, it's an easy thing. For others, the students especially, when you get somebody on the phone that’s pressuring you for money and you’re scared, the brain’s telling you this: ‘There's something wrong here.’

“But your blood pressure and your heart are telling you, ‘Oh my gosh, (...) I'm in panic mode. I need to listen and get this done because I have an emergency,’” said Christina Lehnertz, director, Immigration Compliance and Advising, International Programs and Services at George Mason University in Virginia.

As a way to help differentiate among scams, Lehnertz says international students should be aware of the information they put online, especially in surveys. Red flags include submitting credit card information, their date of birth or Social Security numbers.

“Getting them to be able to tell the difference between a real survey, a real online survey and something that is phishing -- that's a challenge,” Lehnertz said. Phishing is an attempt to obtain sensitive information by fraudulent means.

Young people are not the only targets for scammers and hackers.

“Many grandparents get those kinds of calls as well. Or parents get those calls that … their child or their grandchild is in jail, they need to send money immediately,” Assaf added.

A recent scam uses an app to manipulate photos of people -- mostly women -- with clothes on to make them look like their clothes are off. If a scammer sent a text to female students threatening to publish nude photos unless a ransom is paid, the students might be so embarrassed -- especially if they are from a more modest culture -- that they would wire money to buy the photos.

“If someone is pressuring you to do something, that’s fake,” Bakar said in an interview with VOA.

Assaf says that people are becoming smarter about recognizing scams but are still bad at it. Assaf adds that students need to realize that scamming happens anywhere and to anyone.

Experts say there are ways to tell if someone is scamming you:

· The caller pretending to be from the U.S. government asks for money. Real government officials never ask for money over the phone.

· There is pressure for students to pay now rather than letting them pay later.

· The officials do not give students time to think about the situation overall.

When asked what advice she would give international students to avoid scams, Assaf offered this: “911 will never call you,” she said. “You call them.”