Infection on macOS followed by Wi-Fi router compromise
Infection on macOS followed by Wi-Fi router compromise
Hello everyone, I own a MacBook Air M1 from 2020 with macOS Sonoma 14.0. About three weeks ago I was looking for some wallpapers to display on my screen and found an interesting one. After downloading it with Chrome, I tried to open it by pressing the spacebar or using the preview feature, but it didn’t work as expected. It displayed a new error message that I hadn’t seen before in this version of macOS. I became worried it might be malware and ran every antivirus scan I could find—after installing them—but none detected any threats. Everything seems to be running normally now. I have several questions about what happened, and I’d appreciate any advice from someone with experience.
1. Is it possible my Mac got malware from that image file?
2. Could this file have installed a malicious app in the background without me realizing?
3. If my Mac was infected, could the malware spread to my Wi-Fi router and affect other devices like Windows or Android?
4. I didn’t have antivirus software before, but after everything went wrong, could it have altered the installation or hidden itself so it passed scans?
5. Might there be any spyware that’s already in the system but isn’t active now but could become active later?
6. What should I do now besides wiping the OS and reinstalling? Could malware remain hidden and return after a fresh install?
Please let me know if you have any insights. I’m really concerned.
A Mac can be infected by malware through executable files or by opening them in applications with known weaknesses. The second method is rare unless there’s a specific vulnerability and the software was deliberately aimed at Mac users. If a file takes advantage of a flaw, it could potentially cause harm. Otherwise, an image isn’t as dangerous as an executable since it doesn’t actively perform actions. For exploitation, the image would need to be specially crafted for a recognized weakness in the viewer you use—very unlikely, though not impossible. If infected, malware might interfere with the operating system or block security tools, but this would require advanced techniques. Technically feasible, but highly improbable without specific details about the download. Most scenarios remain theoretical and unlikely unless there’s a clear motive for targeting.
Thanks for your message. It sounds like you're feeling really anxious lately. I'm here to help you work through it. Have you ever dealt with something similar to malware or digital threats?
I believe my work machine has never been infected before. Malware targeting Macs does exist, though images are less typical a threat. More often they appear inside an executable you run. I remember there was a past issue with Zip files that could be used if infected. Probably the download got damaged or the image format isn’t compatible with your Mac. We can't be sure because you didn’t mention the exact error message.
The system displayed an error indicating an unsupported file type. Regarding your concern, installing antivirus software may help detect and block malicious activity, but it cannot guarantee complete protection against all threats.
The file type might not be directly supported by macOS. Could you share the name of the file? It could be a compressed archive like 7z that needs extra tools to open. Some malicious software may block security updates or interfere with them. If possible, let me know the exact name so I can help further.