Australian hackers are taking junk mail to a new level.

Police are warning residents of Pakenham in Victoria, about 50 miles southeast of Melbourne, about corrupt USB flash drives someone is leaving in area mailboxes. Those who insert the drives into computers are being hit with malware.

"The USB drives are believed to be extremely harmful and members of the public are urged to avoid plugging them into their computers or other devices," said Victoria Police media officer Luke Zammit.

According to the New York Times, the sticks contain ransomware, which allows hackers to take control of your PC until you pay up, often in bitcoin so as not to be detected. At least two or three people have fallen for the hoax so far.

It's an old trick. Scammers will often drop USB sticks in parking lots, for example, in the hopes that someone will plug them in, unleash malware, and unknowingly provide a backdoor into their personal data. But large organizations like hospitals have also fallen prey to such exploits. Some of you might have seen it in action on Emmy-winning drama Mr. Robot, which targeted a heavily guarded prison network with the scheme.

Earlier this year, a group of researchers from the University of Illinois Urbana-Champaign conducted an experiment in which they scattered 297 USB flash drives across campus. What they found was that nearly every drive (about 98 percent) was picked up and moved; at least half of the sticks were actually plugged into a computer.

Victoria Police ask that anyone with information about the scammers should contact Crime Stoppers or submit a confidential report online.