The threat described is a malspam campaign distributing the Locky ransomware via email attachments dated May 25, 2016. The malicious payload is delivered as a JavaScript (.js) file compressed within a ZIP archive. When a user extracts and executes the .js file, it triggers the Locky ransomware infection process. Locky ransomware encrypts files on the victim's system, rendering them inaccessible and demanding a ransom payment for decryption. The use of JavaScript in a ZIP file is a common social engineering tactic to bypass email filters and trick users into executing the malware. Although this specific campaign dates back to 2016, Locky was a widespread ransomware strain that caused significant damage globally. The campaign's low severity rating likely reflects the age of the threat and the absence of active exploitation currently. However, the infection vector remains relevant as similar malspam campaigns continue to use compressed JavaScript files to deliver ransomware and other malware. The technical details indicate a low threat level and no known exploits in the wild beyond the malspam distribution method. No specific affected software versions or patches are noted, as the threat exploits user interaction rather than software vulnerabilities.

For European organizations, the impact of a Locky ransomware infection can be severe, especially for entities lacking robust backup and recovery strategies. Locky encrypts a wide range of file types, potentially disrupting business operations, causing data loss, and incurring financial costs from ransom payments and downtime. Critical sectors such as healthcare, finance, and government are particularly vulnerable due to the sensitive nature of their data and the operational disruption ransomware causes. Although this campaign is historical, the infection vector remains relevant, meaning organizations that do not maintain strong email security and user awareness remain at risk. The impact extends beyond direct financial loss to reputational damage and regulatory penalties under GDPR if personal data is affected and not properly protected or restored.

European organizations should implement multi-layered defenses against malspam and ransomware threats. Specific recommendations include: 1) Deploy advanced email filtering solutions capable of detecting and quarantining compressed archives containing executable scripts like .js files. 2) Enforce strict attachment handling policies that block or sandbox suspicious file types, especially scripts within archives. 3) Conduct regular user awareness training focused on recognizing phishing and malspam tactics, emphasizing the risks of opening unexpected attachments. 4) Maintain comprehensive, tested offline backups of critical data to enable recovery without paying ransom. 5) Employ endpoint protection solutions with behavioral detection to identify and block ransomware activity post-execution. 6) Implement application whitelisting to prevent unauthorized execution of scripts and binaries. 7) Keep all systems and security tools updated to reduce the attack surface. These measures go beyond generic advice by focusing on the specific infection vector (JavaScript in ZIP) and ransomware behavior.