Magniber Spreads Through Fake Updates

The threat actors are distributing Magniber ransomware as an update through modern web browsers in ongoing campaign.

The operators behind it are actively exploiting the Internet Explorer (IE) vulnerabilities for the last couple of years. Apart from Internet Explorer (IE), currently, the hackers are also exploiting the modern web browsers:-

Microsoft Edge
Google Chrome

Technical Analysis

In the image below the distribution pages are shown that are opened in Microsoft Edge and Google Chrome, prompting users to install the fake update package with “.appx” extension.

This fake Chrome or Edge’s Windows update package with .appx extension contains an authentic certificate which makes it look legit and allows the installation of the fake package.

Later, in the child paths of C:\Program Files\WindowsApps when the fake downloaded APPX package was executed, it automatically puts the maliciously crafted EXE and DLL files with the following name:-

For EXE file: wjoiyyxzllm.exe
For DLL file: wjoiyyxzllm.dll

Now here at this stage, the wjoiyyxzllm.exe file loads the wjoiyyxzllm.dll to execute a distinct function that is dubbed as “mbenooj.” After completing these stages now the Magniber ransomware gets deployed from the memory of wjoiyyxzllm.exe.

The ransomware starts encrypting all the files present on the user’s system and leaves a ransom note after completing the encryption procedure. They chose the APPX files due to their wide usage.