Scammers do not discriminate. They will go after any group within the population that they think they can pull one over on.
Immigrants are vulnerable to scams largely because of the language barrier. But these criminals also prey on the desperation of some migrants who simply just want to live in the United States. The U.S. Citizenship and Immigration Services tries to stay on top of scams impacting those moving to the U.S. so they can put out warnings and protect these people.
Fake emails asking employers to submit I-9 forms are one way criminals steal information. They are also very good at this scam, making the emails seem legitimate with fake letterheads and websites. However, all links should only go to a .gov website if it is real, and these scams do not.
Another trick these criminals use is asking for payments via MoneyGram, PayPal and gift cards to pay for fees associated with the immigration process. The USCIS notes it will never ask for payments like this via phone or email. The only way it accepts money is on the pay.gov website.
The visa lottery is a system by which people can secure a visa due to the limited number provided each year. The scam makes it seem like someone won the lottery and needs to contact USCIS. However, the USCIS does not handle this system, the U.S. Department of State does, and alerts never come by email.
The general rule when it comes to immigration scams is for people to pay attention. The USCIS will never send a person to a website not affiliated with the U.S. government. It will not ask for money through unusual payment methods, and communications are usually formal in nature. If anything seems questionable, then you should contact the USCIS to validate.