Process Reimaging: A Cybercrook’s New Disguise for Malware
Updated: Aug 26, 2019
As of early 2019, Windows 10 is running on more than 700 million devices, including PCs, tablets, phones, and even some gaming consoles. However, it turns out the widespread Windows operating system has some inconsistencies as to how it specifically determines process image file locations on disk. Our McAfee Advanced Threat Research team decided to analyze these inconsistencies and as a result uncovered a new cyberthreat called process reimaging. Similar to process doppelganging and process hollowing, this technique evades security measures, but with greater ease since it doesn’t require code injection. Specifically, this technique affects the ability for a Windows endpoint security solution to detect whether a process executing on the system is malicious or benign, allowing a cybercrook to go about their business on the device undetected.
Let’s dive into the details of this threat. Process reimagining leverages built-in Windows APIs, or application programming interfaces, which allow applications and the operating system to communicate with one another. One API dubbed K32GetProcessImageFileName allows endpoint security solutions, like Windows Defender, to verify whether an EXE file associated with a process contains malicious code. However, with process reimaging, a cybercriminal could subvert the security solution’s trust in the windows operating system APIs to display inconsistent FILE_OBJECT names and paths. Consequently, Windows Defender misunderstands which file name or path it is looking at and can no longer tell if a process is trustworthy or not. By using this technique, cybercriminals can persist malicious processes executing on a user’s device without them even knowing it.
So, the next question is — what can Windows users do to protect themselves from this potential threat? Check out these insights to help keep your device secure:
Update your software. Microsoft has issued a partial fix that stops cybercriminals from exploiting file names to disguise malicious code, which helps address at least part of the issue for Windows Defender only. And while file paths are still viable for exploitation, it’s worth updating your software regularly to ensure you always have the latest security patches, as this is a solid practice to work into your cybersecurity routine.
Work with your endpoint security vendor. To help ensure you’re protected from this threat, contact your endpoint security provider to see if they protect against process reimaging.
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