By: John Schnaufer
This article was about malware targeted against Macs that can be hidden in the Mac app store. The writer of the article says that although they found the vulnerability, no one has used it yet from what they can see.
This attack could be used by bypassing the code signing done before submission to the app store. The code signature checks or code signing is basically virtual security checks, to make sure the app is safe and stable. It was noticed that the code only gets checked once, and then the signature doesn’t get checked again. This means that an attacker can make a clean app, submit it to the app store, and then once it gets downloads from users, release an update infected with malware for the users to download. They can also steal or buy real code signatures and put them into their malicious app and it has the possibility of getting published to the app store for everyone to download.
The writer of the main article says, “As a result of this research, Reed himself added code signature verification to Malwarebytes Mac products so they now perform a check every time they launch.” Reed works at the company Malwarebytes and he put out an update to their software to check the code signature again of updates to apps. He even says, “A script kiddie could pull off something like this.” This shows how something should be done to fix this problem before others catch on and start infecting peoples computers with malware. This was released recently, so hopefully, it gets fixed soon. I remember when I made my app for the app store and I do not ever remember any checks being done to my updates after the initial release.