The threat described is a malspam campaign identified on August 29, 2016, involving malicious JavaScript (.js) files compressed within ZIP archives. This campaign, labeled "Commission," distributes malware via email attachments designed to entice recipients into opening the ZIP files and executing the embedded JavaScript. Such scripts typically perform malicious actions, including downloading additional payloads, establishing persistence, or stealing information. The campaign leverages social engineering techniques to convince users to open the attachments, often masquerading as legitimate business communications related to commissions or financial transactions. Although the campaign dates back to 2016 and is classified with a low severity and threat level 3, the use of JavaScript in ZIP files remains a common vector for malware delivery. The absence of known exploits in the wild and lack of specific affected software versions suggest this is a generic malware distribution method rather than a targeted vulnerability exploitation. The technical details are limited, with no specific malware family or behavior described, and no indicators of compromise provided. The campaign's impact relies heavily on user interaction, specifically opening and executing the malicious JavaScript, which can lead to compromise of confidentiality and integrity if successful.

For European organizations, this malspam campaign poses a risk primarily through social engineering and user interaction. If users open the malicious ZIP attachments and execute the JavaScript, attackers could gain unauthorized access to systems, potentially leading to data theft, credential compromise, or further malware infection. The impact is more pronounced in sectors with high volumes of email communications involving financial transactions or commissions, such as banking, insurance, and sales organizations. While the campaign's low severity and lack of known exploits suggest limited immediate threat, organizations with less mature email filtering or user awareness programs may be more vulnerable. The campaign could also serve as a foothold for more advanced persistent threats if initial infection occurs. Given the age of the campaign, its direct impact today may be limited, but similar tactics remain relevant, emphasizing the need for continued vigilance.

To mitigate this threat, European organizations should implement advanced email filtering solutions capable of detecting and quarantining suspicious ZIP attachments containing JavaScript files. Specifically, email gateways should be configured to block or flag compressed archives with executable scripts. User awareness training must emphasize the risks of opening unexpected attachments, especially those related to financial topics like commissions. Endpoint protection platforms should be updated to detect and block malicious JavaScript execution. Network monitoring for unusual outbound connections following email receipt can help identify infections early. Additionally, organizations should enforce the principle of least privilege to limit the impact of any successful execution. Implementing application whitelisting can prevent unauthorized script execution. Regular phishing simulation exercises can improve user resilience against such social engineering tactics. Finally, maintaining up-to-date backups ensures recovery capability in case of compromise.