IceXLoader, an updated version of a malware loader, is suspected of infecting thousands of Windows machines worldwide for private and corporate customers.
IceXLoader is a commercially available malware that costs $118 for a lifetime license in underground forums. It is mainly used to download and run additional malware on compromised computers. The malware strain was written in Nim, a relatively new programming language.
It is distributed via emails containing ZIP files that install the malware on the infected computer. Infected individuals download a ZIP file that contain an executable.exe that automatically downloads an image that allows infection with ICeXLoader.
The extractor creates a new hidden folder (.tmp) under “C \Users\\AppData\Local\Temp” and drops the next-stage executable, ‘STOREM~2.exe.’
The infected system will then restart, and a new registry key will be added to delete the temp folder when the computer reboots, depending on the extract settings chosen by the operator.
The dropped executable is a downloader that retrieves a PNG file from a tightly encrypted URL and converts it into the IceXLoader payload, an obfuscated DLL file.
To avoid sandboxes, the dropper checks to make sure it is not running in an emulator and waits 35 seconds before executing the malware loader.
Finally, IceXLoader is injected into the STOREM2.exe process via process hollowing.
In addition, the malware generates a.bat file that disables Windows Defender in real time and adds exclusions to avoid detection.
The commands include the ability to restart, uninstall, and pause the execution of the malware loader, but its primary function is to download and execute next-level malware to disk or memory.
The sources for this piece include an article in BleepingComputer.