Should I be concerned about this malware on mac?

You received an antivirus alert identifying OSX/Amos.ext on your MacBook Air running macOS 15.8. You have quarantined the detected item, which is the correct first step. However, the alert alone does not establish whether the malware ran or whether any personal information was accessed.

AMOS (Atomic Stealer) is malware designed to target macOS computers. Depending on how it is delivered and whether it successfully executes, it can steal sensitive information, including saved passwords and browser data.

How might it have got onto your Mac?

You mentioned DuckDuckGo, but that is a clue rather than proof of the source. DuckDuckGo is a legitimate search engine and also offers a browser. Simply using either does not normally infect a Mac.

One possibility is that you encountered a deceptive website or advertisement, downloaded a malicious file, or followed instructions that caused a harmful command to run. Some AMOS campaigns disguise malicious activity as legitimate software downloads or troubleshooting instructions.

If you only visited a webpage, that is different from downloading and running an installer or entering a command in Terminal. We cannot determine which, if any, of these scenarios occurred from the detection name alone.

What should you do now?

Keep the detected item quarantined. Update your antivirus software and run a full scan. Do not restore or open the file.

If you downloaded an unfamiliar application, ran a command in Terminal, or entered your Mac password into an unexpected prompt around that time, that information would help determine whether further precautions are necessary. If there is evidence that the malware executed, review the security of your important accounts and change potentially exposed passwords from a trusted device.

Apple provides information about its built-in malware protections in its macOS security guide.

Please post the complete warning, including the affected file(s) reported, if any.

Also please tell us what the anti-malware vendor (Intego) has told you about their app, and this report.

deblg wrote:

Just go notified via my virus software that I had this malware on my mac. OSX/Amos.ext. my research suggests that this is specifically targeting mac computers. any insights how this got on my computer? is mentions duckduckgo but i did not understand what was going on or how i got it. i have it quarantined.

What is "my virus software"?

Do not install third party anti virus apps. See this user tip:

Effective defenses against malware and ot… - Apple Community

deblg wrote:

I use Intego Virus Barrier. A while back i had a virus and Apple support had recommended Malware Bytes software to deal with it because the Apple operating system was not able to handle it. From that point on, I always use anti virus software per Apple Help Desk recommendation.

Part 1 of 2

Windows-like viruses that self-replicate and affect macOS don’t exist because of the underlying UNIX Foundation and permission limitations.

The macOS operating system resides in a sealed and read-only volume that can’t be opened by users or third-party applications.

Mac app security enhancements are sufficient to protect computers from malware.

Effective defenses against malware and other threats

Adware and Malware can affect computers and are often downloaded from “shady” websites or developers who inject them into downloads.

Source: User tip from @Kurt Lang

What is malware? - Apple Community

Part 2 of 2

There are 5 Categories of Third Party Software / Services that are not needed 

Get rid of them via the Developers Instruction 

In no special order 

1 - Third Party 2 Way Firewalls 

like Lulu and Little Snitch 

2 -Commercial VPNs 

They may not be what one believes they are doing for the computer and what they actually are doing behind the scenes and unbeknownst to the user ( you ) 

They may also reduce your Internet Speeds significantly 

https://gist.github.com/joepie91/5a9909939e6ce7d09e29

VPN: What you need to know - Apple Community

3 - Third Party Security Software 

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX  Foundation and Permission Limitation. 

The Operating System resides in a Sealed and Read Only Volume that cannot be opened by the User nor by Third Party Applications.

The Only thing this Antivirus software is protecting is the Bank Account of the Developers and for zero return to the User aside from the problems this software creates.

Mac app security enhancements

The Built in Security  is all that is required to protect the computer.

Protecting against malware in macOS

4 - Third Party Disk Cleaners / Optimizer 

Any Third Party Applications that will interfere with the normal operation of the OS,  is an invitation for disaster. 

Certain Applications maybe available on the Apple Apps Store - this only means the Developer is prepared to pay Apple a percentage on each sale. 

What the Application may do to the computer is up to the User to check this out before purchase

To put the Third Party Disk Cleaner / Optimizer in context and the damages it may have or has already done.

This type of applications can or will Muck Up your User Account ( Home Folder ) of this machine.

It does not touch the Operating System itself, unless you consider your User Account ( Home Folder ) as part of the Operating System.

Then, the user’s environment has been badly compromised ( hosed ) to the extent that the whole system is unstable and unreliable 

5 - All in One 

"Avast Compressor" is not a standalone product, but rather a functional component of Avast Cleanup Premium (also available in Avast One), which is designed to free up disk space and improve device performance by compressing or optimizing large files and media

I use Intego Virus Barrier. A while back i had a virus and Apple support had recommended Malware Bytes software to deal with it because the Apple operating system was not able to handle it. From that point on, I always use anti virus software per Apple Help Desk recommendation.