Google is so helpful now when you ask it to solve a problem, such as how to free up space on your Mac. Not only can it make its own suggestions, but it can tap into those from AIs like ChatGPT and Grok. This article shows how that can bring you malware, thanks to the recent research of Stuart Ashenbrenner and Jonathan Semon at Huntress.

Please don’t try anything you see in this article, unless you want AMOS stealer malware on your Mac.

I started by entering a common search request, clear disk space on macOS, the sort of thing many Mac users might ask.

At the top of Google’s sponsored results is an answer from ChatGPT, giving its trusted web address. When I clicked on that, it took me to ChatGPT, where there’s a nice clear set of instructions, described impeccably just as you’d expect from AI.

This helpfully tells me how to open Terminal using Spotlight, very professional.

It then provides me with a command I can copy with a single click, and paste straight into Terminal. It even explains what that does.

When I press Return, I’m prompted for my password, which I enter.

Although I was a bit surprised to see this prompt, it looks genuine, so I allowed it.

Far from clearing space on my Mac, the malware, an AMOS stealer, has gone to work, saving a copy of the password I gave it, in the /tmp folder, and installing its payload named update.

Scripts like .agent are installed in my Home folder, and my (virtual) Mac is now well and truly owned by its attacker.

Full technical details are given in this post from Huntress.

As Ashenbrenner and Semon point out, this marks a new and deeply disturbing change, that we’re going to see much more of. We have learned to trust many of the steps that here turn out to lead us into trouble, and there’s precious little that macOS can do to protect us. This exploit relies almost entirely on our human weakness to put trust in what’s inherently dangerous.

First, distrust everything you see in search engines. Assess what they return critically, particularly anything that’s promoted. It’s promoted for a reason, and that’s money, so before you click on any link ask how that’s trying to make money from you. If that’s associated with AI, then be even more suspicious, and disbelieve everything it tells you or offers. Assume that it’s a hallucination (more bluntly, a lie), or has been manipulated to trap you.

Next, check the provenance and authenticity of where that click takes you. In this case, it was to a ChatGPT conversation that had been poisoned to trick you. When you’re looking for advice, look for a URL that’s part of a site you recognise as a reputable Mac specialist. Never follow a shortened link without unshortening it using a utility like Link Unshortener from the App Store, rather than one of the potentially malicious sites that claims to perform that service.

When you think you’ve found a solution, don’t follow it blindly, be critical. Never run any command in Terminal unless it comes from a reputable source that explains it fully, and you have satisfied yourself that you understand exactly what it does. In this case the command provided was obfuscated to hide its true action, and should have rung alarm bells as soon as you saw it. If you were to spare a few moments to read what it contains, you would have seen the command curl, which is commonly used by malware to fetch their payloads without any quarantine xattr being attached to them. Even though the rest of the script had been concealed by base-64 encoding, that stands out.

If you did get as far as running the malicious script, then there was another good clue that it wasn’t up to anything good: it prompted you for a System Password:. The correct prompt should just be Password:, and immediately following that should be a distinctive key character that’s generated by macOS for this purpose. Then as you typed your password in, no characters should appear, whereas this malware showed them in plain text as you entered them, because it was actually running a script to steal your password.

Why can’t macOS protect you from this? Because at each step you have been tricked into bypassing its protections. Terminal isn’t intended to be a place for the innocent to paste obfuscated commands inviting you to surrender your password and download executable code to exploit your Mac. curl isn’t intended to allow malware to arrive without being put into quarantine. And ad hoc signatures aren’t intended to allow that malicious code to be executed.

As I was preparing this article Google search ceased offering the malicious sponsored links, but I expect they’ll be back another time.

AI is certainly transforming our Macs, in this case by luring us to give away our most precious secrets. This isn’t a one-off, and we should expect to see more, and more sophisticated, attacks in the future. Now is the time to replace trust with suspicion, and be determined not to fall victim.