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Why You Shouldn't Plug Unknown Devices Into Your Computer

And how macOS Ventura helps protect you

By Charlie Sorrel Charlie Sorrel Senior Tech Reporter Charlie Sorrel has been writing about technology, and its effects on society and the planet, for 13 years. lifewire's editorial guidelines Published on June 27, 2022 10:32AM EDT Fact checked by Jerri Ledford Fact checked by Jerri Ledford Western Kentucky University Gulf Coast Community College Jerri L. Ledford has been writing, editing, and fact-checking tech stories since 1994. Her work has appeared in Computerworld, PC Magazine, Information Today, and many others. lifewire's fact checking process Tweet Share Email Tweet Share Email Internet & Security Mobile Phones Internet & Security Computers & Tablets Smart Life Home Theater & Entertainment Software & Apps Social Media Streaming Gaming Macs running Ventura will require user permission to connect to USB-C and Thunderbolt accessories.This only works on Apple Silicon Macs, and right now, only the laptops. Never plug an unknown USB device into your computer, ever. Brina Blum / Unsplash In 2010, news emerged of a computer worm designed to hobble Iran's nuclear program, called Stuxnet, that was planted using USB thumb drives. If only they'd had macOS Ventura back then. In macOS Ventura, Apple has closed one big security hole. The Mac will no longer allow any old USB device to connect when you plug it in. Instead, in a model much like that on the iPad and iPhone, plugging in a USB device will prompt the user for approval. "It is a terrible idea to connect unknown devices to your computer. Hackers consider USB devices to be an 'attack vector' or a weakness that might grant them access to a computer or network. Get someone to connect a drive infected with malware to a computer, and you're in," Travis Lindemoen, managing director of Nexus IT Group, told Lifewire via email.

US B Careful

Most everyday attacks on computers come over the internet. This is why we are trained not to click on email links and to be vigilant about what we connect our computers to. But that's not the only way to attack a computer. Some of the worst exploits get dismissed as being a danger because they require physical access to your machine. It used to be that once an attacker had your computer in their hands, all bets were off. They only needed time, and they'd have access to everything. Then came the iPhone, which Apple has progressively hardened until today. It's not even worth stealing one because the thief cannot unlock it. It is a terrible idea to connect unknown devices to your computer. Macs have gotten better at this too, and now that they run on the same basic chips as the iPhone and iPad, they benefit from this physical security. But even then, USB is a prime vector for delivering malware, partly because it can get past outward-looking defenses like firewalls, etc.

Hackers They re Not Interested in Me

Stuxnet was a targeted attack, designed to monkey with the controllers from Siemens, which are used in many industrial processes. While it spread throughout computers worldwide, it had one target: the centrifuges used in Iran's uranium enrichment facility. The beauty of using USB as a vector is that it can infect computers that are forever kept offline for security purposes. Now, unless you are a prominent industry or government figure, it is unlikely that you will be a direct target like that. But that's not the only point of an attack. Good old-fashioned malware can be spread over USB, too. Or ransomware, which encrypts the data on your computer's hard drive and demands a payment to unlock it. "I'm sure that you also rationalize these fears away by telling yourself that no one would get near your Mac armed with anything like those custom USB-C or Thunderbolt devices. But what if it's a notebook, and you fall asleep on the train while using it? Or it's misplaced or stolen?" says Mac system spelunker and expert Howard Oakley on his Eclectic Light Company blog. Malware can spread by hopping from computer to computer via USB. An infected computer will load the malware onto any thumb drive the user attaches, and then it will wait until it's connected to another machine. Marcus Urbenz / Unsplash But it can also be built into cables and chargers. That's right. If you plug your phone into a charger at the local coffee shop, that charger could be delivering its payload while you order your ridiculously complicated non-coffee beverage. It can even be built into a Lightning cable, which is a good reason only to buy cables from reputable vendors and ensure you're not getting a counterfeit. Ventura's new Accessory Security feature can help with this, but once you give a connected USB device your permission, you still might get infected. The feature also doesn't protect against devices connected to approved USB hubs, power adapters, or displays. On the other hand, if you're a character in a TV show or a movie, and an adversary tries to install some tracking software on your computer via a USB stick, they will be stymied. As long as the scriptwriters remembered to install the latest version of macOS on your imaginary computer. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit More from Lifewire How to Choose an External Hard Drive How to Connect USB Devices to an iPad 6 Ways to Connect Your Computer to Your TV USB4: Everything You Need to Know USB (Universal Serial Bus): Everything You Need to Know How to Install and Connect a Webcam to Your PC How to Add Bluetooth to Your Computer How to Protect Your iPad From Malware and Viruses How to Boot From a USB Device Why Your Computer is So Slow and 16 Ways to Fix It Are iPads Really That Safe from Viruses and Malware? How to Burn an ISO File to a USB Drive How to Connect an Android to a PC Is Google Play Safe? Can a Router Get a Virus? How to Transfer Photos From any Phone to Your Computer Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies