Researchers Demonstrate Subliminal Smart Device Commands That Have Potential for Malicious Attacks

Researchers in the United States and China have been performing tests in an effort to demonstrate that "hidden" commands, or those undetectable to human ears, can reach AI assistants like Siri and force them to perform actions their owners never intended. The research was highlighted in a piece today by The New York Times, suggesting that these subliminal commands can dial phone numbers, open websites, and more potentially malicious actions if placed in the wrong hands.

A group of students from the University of California, Berkeley and Georgetown University published a research paper this month, stating that they could embed commands into music recordings or spoken text. When played near an Amazon Echo or Apple iPhone, a person would just hear the song or someone speaking, while Siri and Alexa "might hear an instruction to add something to your shopping list." Or, more dangerous, unlock doors, wire money from your bank, and purchase items online.

siri iphone x
The method by which the students were able to accomplish the hidden commands shouldn't be a concern for the public at large, but one of the paper's authors, Nicholas Carlini, believes malicious parties could already be making inroads with similar technology.

“We wanted to see if we could make it even more stealthy,” said Nicholas Carlini, a fifth-year Ph.D. student in computer security at U.C. Berkeley and one of the paper’s authors.

Mr. Carlini added that while there was no evidence that these techniques have left the lab, it may only be a matter of time before someone starts exploiting them. “My assumption is that the malicious people already employ people to do what I do,” he said.

Last year, researchers based at Princeton University and Zheijiang University in China performed similar tests, demonstrating that AI assistants could be activated through frequencies not heard by humans. In a technique dubbed "DolphinAttack," the researchers built a transmitter to send the hidden command that dialed a specific phone number, while other tests took pictures and sent text messages. DolphinAttack is said to be limited in terms of range, however, since it "must be close to the receiving device."

DolphinAttack could inject covert voice commands at 7 state-of-the-art speech recognition systems (e.g., Siri, Alexa) to activate always-on system and achieve various attacks, which include activating Siri to initiate a FaceTime call on iPhone, activating Google Now to switch the phone to the airplane mode, and even manipulating the navigation system in an Audi automobile.

In yet another set of research, a group at the University of Illinois at Urbana-Champaign proved this range limitation could be increased, showing off commands received from 25 feet away. For the most recent group of researchers from Berkeley, Carlini told The New York Times that he was "confident" his team would soon be able to deliver successful commands "against any smart device system on the market." He said the group wants to prove to companies that this flaw is a potential problem, "and then hope that other people will say, 'O.K. this is possible, now let's try and fix it.'"

For security purposes, Apple is stringent with certain HomeKit-related Siri commands, locking them behind device passcodes whenever users have passcodes enabled. For example, if you want to unlock your front door with a connected smart lock, you can ask Siri to do so, but you'll have to enter your passcode on an iPhone or iPad after issuing the command. The HomePod, on the other hand, purposefully lacks this functionality.

Popular Stories

iPhone 16 Pro Sizes Feature

iPhone 16 Series Is Just Two Months Away: Everything We Know

Monday July 15, 2024 4:44 am PDT by
Apple typically releases its new iPhone series around mid-September, which means we are about two months out from the launch of the iPhone 16. Like the iPhone 15 series, this year's lineup is expected to stick with four models – iPhone 16, iPhone 16 Plus, iPhone 16 Pro, and iPhone 16 Pro Max – although there are plenty of design differences and new features to take into account. To bring ...
Apple Watch Series 9

2024 Apple Watch Lineup: Key Changes We're Expecting

Tuesday July 16, 2024 7:59 am PDT by
Apple is seemingly planning a rework of the Apple Watch lineup for 2024, according to a range of reports from over the past year. Here's everything we know so far. Apple is expected to continue to offer three different Apple Watch models in five casing sizes, but the various display sizes will allegedly grow by up to 12% and the casings will get taller. Based on all of the latest rumors,...
iPhone 16 Pro Left Side Feature

iPhone 16 Pro Again Rumored to Come in New 'Rose' Color

Tuesday July 16, 2024 3:53 am PDT by
Apple's upcoming iPhone 16 Pro and iPhone 16 Pro Max will be available in a new "Rose" color, claims a rumor out of China, corroborating previous claims. Chinese Weibo-based leaker OvO Baby Sauce OvO, a relatively new source of supply chain leaks, said on Tuesday that the new color code for the iPhone 16 Pro models is simply "Rose," not the previous "Rose Gold" color that Apple first offered ...
New MacBook Pros Launching Tomorrow With These 4 New Features 2

M5 MacBook Models to Use New Compact Camera Module in 2025

Wednesday July 17, 2024 2:58 am PDT by
Apple in 2025 will take on a new compact camera module (CCM) supplier for future MacBook models powered by its next-generation M5 chip, according to Apple analyst Ming-Chi Kuo. Writing in his latest investor note on unny-opticals-2025-business-momentum-to-benefit-509819818c2a">Medium, Kuo said Apple will turn to Sunny Optical for the CCM in its M5 MacBooks. The Chinese optical lens company...
tinypod apple watch

TinyPod Turns Your Apple Watch Into an iPod

Wednesday July 17, 2024 3:18 pm PDT by
If you have an old Apple Watch and you're not sure what to do with it, a new product called TinyPod might be the answer. Priced at $79, the TinyPod is a silicone case with a built-in scroll wheel that houses the Apple Watch chassis. When an Apple Watch is placed inside the TinyPod, the click wheel on the case is able to be used to scroll through the Apple Watch interface. The feature works...
macbook pro january

Best Buy's Black Friday in July Sale Takes Up to $700 Off M3 MacBook Pro for Members

Monday July 15, 2024 11:05 am PDT by
Best Buy's "Black Friday in July" sale is in full swing today, and in addition to a few iPad Air discounts we shared earlier, there are also some steep markdowns on the M3 MacBook Pro. You will need a My Best Buy Plus or Total membership in order to get some of these deals. Note: MacRumors is an affiliate partner with Best Buy. When you click a link and make a purchase, we may receive a small...

Top Rated Comments

nwcs Avatar
81 months ago
This is really clever. I wouldn’t have thought that the AIs would respond to non-vocal frequencies as they’re intended to listen to humans only. I would think that checking the frequency range of the command would be enough to counteract this problem fairly simply.
Score: 18 Votes (Like | Disagree)
daveschroeder Avatar
81 months ago
That is NOT "subliminal".

I think you're looking for another word.
Score: 12 Votes (Like | Disagree)
bluespark Avatar
81 months ago
In fairness, Apple has made great strides in tackling this issue already through Siri's continued uselessness.
Score: 12 Votes (Like | Disagree)
amaier1986 Avatar
81 months ago
HomePod directs me to use my phone to unlock my front door or open my garage doors. This potential issue seems to be somewhat under control with iOS.
Score: 7 Votes (Like | Disagree)
w5jck Avatar
81 months ago
That is NOT "subliminal".

I think you're looking for another word.
My thought is that the word should be "inaudible" and NOT "subliminal". As in, "The devices can react to inaudible commands."
Score: 7 Votes (Like | Disagree)
jarman92 Avatar
81 months ago
This is really clever. I wouldn’t have thought that the AIs would respond to non-vocal frequencies as they’re intended to listen to humans only. I would think that checking the frequency range of the command would be enough to counteract this problem fairly simply.
Agreed. But why wouldn't Apple have foreseen this and limited the frequency range in the first place? There's literally no need for phone mics to detect anything below/above human voice frequencies.
Score: 6 Votes (Like | Disagree)