Russian Sandworm Hackers Adopt ClickFix Technique to Target Ukrainian Organizations

 

Ukraine’s Computer Emergency Response Team (CERT-UA) has issued an advisory after detecting that Russia’s advanced persistent threat (APT) group Sandworm has been using the ClickFix social engineering technique to target devices of interest. ClickFix is a relatively new method that has gained popularity among threat actors in the past year. It involves hosting CAPTCHA pages that mislead users into pasting PowerShell commands that execute malicious scripts on the targeted device.  

According to the advisory, Sandworm began using the technique in the spring of 2026 and has been using it continuously through the summer. CERT-UA researchers found ten websites hosting CAPTCHA pages that redirected users to web pages with malicious PowerShell commands. The commands downloaded Visual Basic scripts and other malicious files, which in turn deployed several malware families known to be used by Sandworm. One of the malware samples detected by CERT-UA is a Python backdoor called FreakyPoll. 

It gained initial access to the targeted system via the described technique and provided remote access to the attackers. The first-stage malware samples have been observed collecting information about the target system to determine its value. For example, the GHETTOVIBE Visual Basic script has been seen attempting to self-perpetuate by storing itself in the Windows Startup folder. Meanwhile, the SCOUTCURL PowerShell script has been collecting information about the operating system, installed software, files, and browser data and exfiltrating the data to the attackers’ infrastructure. 

If the target was valuable, the threat actors used other malware samples to gain persistent access to the system. For example, FluidLeech, a fake antivirus software, and LoadLoop, a loader, were also used in the attacks. CERT-UA researchers have also detected that the actors have been using a custom tool called SMARTAXE to improve the infrastructure used to host CAPTCHA pages. The tool has been observed calling Ethereum smart contracts to retrieve lists of domain names, which the attackers then used to compromise other websites and host malicious CAPTCHA pages. 

Besides using the ClickFix technique, CERT-UA has detected that Sandworm has been using several other methods to compromise devices. The first method, tracked under the name CowardDuck, involves compromising Android devices via malicious apps that steal files from the devices and exfiltrate the data to the attackers’ servers. In the past, Sandworm has been using pirated software to deliver malware to targeted systems and has been using social engineering techniques over the Signal messenger to trick users into installing fake apps.  

The advisory recommends that website administrators and hosting providers scan their websites for web shells and unauthorized extensions. Moreover, the administrators should check whether their websites have been modified to host CAPTCHA pages misleading users into pasting the malicious PowerShell commands.