Does your computer seem to be running slower lately?

You’re not alone. Over time, computers tend to get bogged down. For example, you install a piece of software to accomplish some task you only perform every now and then, but the program requires that a component of itself be running in the background at all times. Or you upgrade your antivirus software—the new version does a better job of filtering out malicious software, but it also needs more system resources to do its job.

Perception also plays a role—the “new” wears off a computer pretty quickly, and what seemed like blinding speed a year ago now feels like you’re trudging through treacle every time you want to fire up a web browser, even if the machine is running just fine.

The net result is that a lot of people think, “Hey, this thing isn’t running as fast as it used to—something must be wrong!” Enter the Slow Computer Scam. It generally targets seniors, but anyone with a computer could fall for it.

It begins with a phone call from a stranger who claims to work for Microsoft. The caller tells the victim that the company has received notification that their computer has been running slowly or is infected with spyware, viruses or other problems.

At this point, if the victim agrees, the call will go one of two directions. In the first variant, the victim is instructed to go to their computer, then fed step-by-step directions by the caller that are supposed to fix the problem. What is actually happening is the victim is handing over control of their computer to a criminal, allowing them to search for files containing personal information, install spyware designed to harvest any data the victim enters, or link the computer to a botnet used to transmit data for organized criminals.

In the second version, the victim will be told that the caller can fix the problem, but only for a fee. They will be instructed to use Western Union to wire a few hundred dollars as payment.

There is a recent double-dip version in which the scammers call the same victim again a few weeks later. This time, they inform the victim that they are from Dell (or whoever manufactured the victims computer), the earlier call from Microsoft was a scam, and that their computer was infected with malware by the scammer. They offer to fix the computer for a fee of several hundred dollars, again to be wired via Western Union.

This may be one of the easiest scams to recognize. If your telephone rings, and someone is on the line telling you that there’s something wrong with your computer, that’s your cue to hang up.

Microsoft does not have a giant control room that keeps tabs on the performance of every computer in the world. Nobody is sitting at a monitor going, “Whoa. Some guy out in Indiana has a slow computer. Perkins! Get on this!”

The same goes for Dell and other computer hardware manufacturers—they don’t have a giant database of who owns their computers or how they’re running. If there’s a problem with your hardware or software, or if your machine is infected with malware, it’s basically on you to figure it out and fix it.

There is also no scenario in which Microsoft, Dell, or any other tech company is ever going to require payment via Western Union. Keep your antivirus software up-to-date, and when a stranger calls to tell you there’s a problem with your computer, hang up.