DENVER (KDVR) — The Colorado State University Police Department is warning community members of calls spoofing the CSU 491 prefix and pretending to be immigration authorities.

Spoofing refers to someone presenting a false identity, making a phone call appear to be coming from a known or trusted number, such as a local business, government agency, or as in this case, an institution of higher education.

CSU police said that the tactic is commonly used in cyberattacks and fraud.

"In this instance, the perpetrator spoofed the CSU information line of 970-491-6444 and claimed to be an immigration authority," the police department said.

Preventing a spoofed call is difficult, as many phone systems support manipulation of caller ID data.

The agency told potential victims that if they receive a call from an unfamiliar number or from a number that looks suspicious, even if it seems local, let it go to voicemail. The agency said that legitimate callers will either leave a message or find another way to contact you.

Spoofers can make a call appear to be from a known organization. If you suspect a call is not what it seems after answering, hang up and call the person or organization back using a different number that you trust, such as from your contact list or their website. Do not call the same number back, as that will likely lead you to the same spoofer.

You can report caller ID spoofing to CSU police at 970-491-6425 or other local law enforcement agencies.