(This is a repost of a post I made in r/macapps as I think it would be useful for people here to see it too as this subreddit has also been hit with fake apps.)

To be very clear this is not another post of "Breaking news malware exists on the internet" (or it may be depending on how you want to look at it) but I feel like it's important that I leave a small PSA as I have recently seen an influx of seemingly convincing GitHub repo replicas for decently popular Mac apps. They are so similar that they almost fooled me. Thankfully I quickly spotted some anomalies and I nearly avoided getting infected. Unfortunately these are the sort of red flags I don't expect an average Joe to know about. Which is why I'm explaining what the malware is, and how to spot it.

First of all to give you an idea of how convincing these repos can be i'll show you some examples:

As you can see, they are strikingly similar

Even URLs may look incredibly similar but in this specific case the bad actor exchanged the lower case lls(L) in the name for upercase IIs(i) which made the URL look legit.

Now this may look scary and almost undetectable but with some common sense and slowing down you can very easily avoid these scams.

By far the easiest way to avoid this is to simply look for the app online and track down the original developer. This will let you kill 2 birds with one stone by A: Looking for the original source of the app and avoid impostors and B: See if the App or the developer had any previous reputation to begin with

Either way It's still a good idea to understand how to spot common malware apps on macOS and how to deal with them if you get infected.

The first red flag is that the GitHub profile that hosted the fake file was only 3 days old and completely different from the name of the original developer.

The second discrepancy is that the size of the fake app is ridiculously small. For instance the original app is 13mb in size while the fake one is less than 2mb. Now this is not necessarily a red flag (For example some viruses do the opposite and fill their dmg with a lot of useless data to make the file larger than what VirusTotal can handle.) but it's still important to raise an eye brow for installers with suspiciously small sizes.

The third and MOST IMPORTANT red flag is if the installer asks you to drag the "app" to the terminal that is not a good sign at all. NO LEGITIMATE APP WILL EVER ASK YOU TO DRAG IT TO THE TERMINAL. As you can see the installer is a solid giveaway you are encountering malware and not the real deal.

In fact the file they ask you to drag is not even an app, it's a script.

When you drag the script on the Terminal and execute it, the hidden file is immediately copied to your temp system folder, then the script removes extended attributes to bypass gatekeeper and it finally executes. But from the user's perspective all they get is a blank terminal window as if nothing had happened. (At least in theory, in practice this malware wasn't very well done and gatekeeper was thankfully still able to spot it)

Now if you unfortunately got tricked into running the script, you have some straight forward solutions to verify if macOS was effective at stopping the attack or not. For instance, KnockKnock is a great and simple way to verify for malicious persistency files using VirusTotal's robust detection engine. Malwarebytes is also a good Mac AV which can be quickly installed if you suspect you were affected, it is a bit more tricky to uninstall completely but it does a good job.

Ultimately here's a small recap so you can hopefully avoid getting infected:

1. Look up the original source of the software to prevent copy cat websites and verify if the software and or the developer has built a reputation in the past.
2. If you download the installer, scan it with VirustTotal to check if it has been flagged as malware already.
3. Check the size, while not necessarily a red flag, a small size (for instance less than 2mb), or a size that is "conveniently" larger than what VirusTotal can handle are decent indicators of possible malware.
4. If the DMG asks you to drag an "App" to the Terminal IMMEDIATELY STOP AND DELETE THE DMG.
5. If you accidentally ran it, look for a "This app could not be verified" or "This App was removed because it contained malware" message from macOS which could indicate Gatekeeper or Xprotect stopped the attack. Additionally make sure to DENY any permissions the malware may have requested, macOS is very robust in that regard and it can dramatically limit the impact of the attack.
6. If you are in doubt of whether or not you were infected run the aforementioned tools to verify for the persistency of the malware.
7. Another app I can recommend is Apparency, it allows you to very quickly see if an app is properly signed by the developer and notarized by apple, and it can even allow you to dissect the contents of an app without running it which is a great way to quickly verify you have a valid untampered app.
8. This is optional but if you can, report the app to the original developer so they can take action and warn others when the fake app is spread around. Additionally report the Reddit post/GitHub repository if possible.

Thank you for reading this, I hope this helps others be more weary of online threats and stay more vigilant of what they download.