Pro-Ukraine Hacking Cat group deploying new malware against Russian targets

Kaspersky links pro-Ukraine hacktivist group Hacking Cat to Gorilla RAT and Monkey Ransomware in destructive attacks on Russian targets.

Kaspersky reports that pro-Ukraine group Hacking Cat, active since February 2024, has shifted from defacements to destructive encryption attacks, using a previously undocumented Gorilla RAT remote-access tool and Monkey Ransomware, which appends the .monkey extension to files. Initial access in some attacks came from exploited Microsoft Exchange vulnerabilities, and rapid multi-language malware variants suggest possible generative AI assistance. Shared tools like Nemo Wiper across groups including Ukrainian Cyber Alliance complicate attribution, and targets include Rosatom contractor and heating provider Donbassteploenergo.