HOUSTON -- The FBI is urging the public to be wary of three frightening e-mails that are circulating and falsely claim to be from the FBI. The e-mails address issues like jeopardizing homeland security and terrorist groups.

The FBI is warning people that these e-mails have nothing to do with any federal agency. The FBI said it does not send unsolicited e-mails and would not e-mail official reports.

Read: Examples Of E-Mails

Each of the messages has an attachment that can harm computers.

"You receive the e-mail, read it, open the attachment, and once you've done that you've most likely infected your computer and now the computer is in the control of the attacker," said computer expert Marc Scarborough. He works at Rice University as an information security officer, watching for viruses on campus every day.

He said the sender in this case is actually a hacker in disguise.

"Most of the time the goal of these sorts of attacks is financial, either to get your information to use at a bank or to use your computer to attack another system later," Scarborough said.

He said that if users have any doubt, then they should take a look at how the e-mails are actually written.

"There are a lot of grammar errors and a lot of misspellings, a lot of things wouldn't associate with a government document in this case," he said.

If you do get one of these e-mails in your in-box, the best thing you can do is simply delete it, Scarborough said.

Read: Examples Of E-Mails