A recent investigation by Aryaka Threat Research Labs has revealed a new version of the Vidar infostealer that demonstrates how cybercriminals are refining existing malware to make it more discreet and effective. Vidar, which has circulated for years through malware-as-a-service platforms, is known for its modular structure that allows operators to customize attacks easily.
The latest strain introduces a significant upgrade: the ability to intercept sensitive information directly through API hooking.
This method lets the malware capture credentials, authentication tokens, and encryption keys from Windows systems at the precise moment they are accessed by legitimate applications, before they are encrypted or secured.
By hooking into cryptographic functions such as CryptProtectMemory, Vidar injects its own code into running processes to momentarily divert execution and extract unprotected data before resuming normal operations.
This process enables it to gather plaintext credentials silently from memory, avoiding noisy file activity that would typically trigger detection. Once harvested, the stolen data which includes browser passwords, cookies, payment information, cryptocurrency wallets, and two-factor tokens is compressed and sent through encrypted network channels that mimic legitimate internet traffic.
The malware also maintains persistence by using scheduled tasks, PowerShell loaders, and randomized installation paths, while employing in-memory execution to reduce forensic traces.
These refinements make it harder for traditional antivirus or behavioral tools to identify its presence.
The evolution of Vidar highlights the need for defenders to rethink detection strategies that depend solely on file signatures or activity volume.
Security teams are encouraged to implement Zero Trust principles, monitor API calls for evidence of hooking, and apply runtime integrity checks to detect tampering within active processes. Using endpoint detection and response tools that analyze process behavior and adopting memory-safe programming practices can further strengthen protection.
Experts warn that Vidar’s development may continue toward more advanced capabilities, including kernel-level hooking, fileless operations, and AI-based targeting that prioritizes valuable data depending on the victim’s environment.
The findings reflect a broader shift in cybercrime tactics, where minor technical improvements have a major impact on stealth and efficiency. Defending against such threats requires a multi-layered security approach that focuses on process integrity, vigilant monitoring, and consistent patch management.
