How to Know if Someone Copied Files From Your USB ?

This is how to tell if someone copied files from your USB flash drive to their computer.

Did you give your USB flash drive away and want to know what files were copied?

This article tells you everything you need to know.

Let’s get started!

Table of Contents

How to Know if Someone Copied Your Files From Your USB to Their Computer?

Data safety has been one of the hot topics for a long time.

How safe are your files?

Where should you store them, and who should have access?

Are cloud drives secure?

To avoid all of these issues, many people choose to play it safe and keep their files on a USB stick.

After all, when your files are stored on a physical device, and you know where that device is, the files will be much safer.

But, on the rare occasions when you loan that device to someone or leave it unsupervised, can you see if your important files have been tampered with?

Unfortunately, your options for doing this are likely more limited than you might think.

USB Drives and Security

USB drives are usually considered safe places to store your data – from a software perspective.

This means that since USB sticks don’t run complex software or get information from a server, they are less likely to be hacked or broken into.

That’s especially the case when they aren’t plugged into your computer. At that point, they’re just pieces of plastic and fiberglass hanging around in your pocket.

However, it might be important to mention that researchers have found that hackers can hide sniffer software in the small chips found in USB sticks. This software would allow the hackers to control the device remotely without the user ever being aware of it.

But, the most significant security concern with a USB flash drive comes from the very fact that it’s a physical device.

Storing important files on a small device that can easily get lost or stolen is hardly a smart move unless you tie it to your wrist or protect it with a password.

Can You Tell if Someone Copied Your Files?

The short answer to this question is—no. There are no reliable ways to tell whether someone copied files from your USB device.

One technique could maybe help you, but it’s far from certain: you can check when each file on your computer or USB device has been last accessed.

And, to copy a file, you have to access it.

Hypothetically, you can check when a file has been last accessed, and the time stamp would be an indicator of when someone copied it.

Even though this is an unreliable technique, it’s pretty easy if you want to use it.

Simply right-click on the file you want to check, and click on “Properties.” There, you’ll see when the file has been created, modified, and last accessed.

There are two main issues with this approach.

Files Are Accessed Regularly

This is a glaring issue: “accessed” doesn’t really have to mean anyone came close to touching your file.

Your PC doesn’t interpret “accessed” as “opened” or “copied.” Files are being accessed regularly by different services running on your computer.

For example, anti-malware tools access files to check them for viruses.

So, if you give your USB to someone, get it back, and check the “accessed” timestamp, chances are you’ll see the moment when they inserted the USB device into their PC.

Their computer likely did a quick virus scan or other types of checks that would modify the “accessed” time.

Also, your PC might execute a check when you insert the device.

Even worse, your antivirus doesn’t need to check for the file access times to be updated.

Simply opening the containing folder with File Explorer might cause it to read the files (maybe to get a preview image) and you’ll lose the access time just like that.

Many USB Drives Don’t Update Access Times

USB flash drives use a file system called File Allocation Table (FAT), unlike your computer that uses a different system called New Technology File System (NTFS).

Here’s the problem: FAT systems don’t track update times. Windows formats all removable storage devices this way, so you most likely won’t get relevant information by checking access times anyway.

How Do You Improve the Safety of Your USB?

How can you ensure that your files aren’t compromised if you do end up losing your USB flash drive?

Here are a few things you can do.

  • Encrypt the data: You can use an encryption tool to protect your data even before you put it on the USB drive. The device trying to interpret it would need to have the same encryption tool installed to read this data.
  • Use an encrypted USB: USB devices use hardware encryption: when inserted into the USB port, they’ll require a password. You create this password the first time you insert the USB into your computer, and the flash drive can’t work without it.
  • Encrypt files on your USB: You can use encryption software to protect specific folders or files on your thumb drive. You can also create hidden partitions for additional security.