The threat described is a malspam campaign identified on September 6, 2016, involving malicious JavaScript (.js) files compressed within ZIP archives. The campaign is titled "Suspected Purchases" and is characterized by emails that likely attempt to trick recipients into opening the attached ZIP files containing the JavaScript payload. Upon execution, the JavaScript malware could perform a variety of malicious activities, such as downloading additional payloads, executing commands, or harvesting information. The campaign uses social engineering tactics by referencing "suspected purchases" to entice users to open the attachment, leveraging common user concerns about unauthorized transactions. Although specific technical details about the malware's behavior are not provided, the use of .js files in ZIP archives is a common vector for delivering malware while bypassing some email filters. The campaign was classified as low severity by the source, with no known exploits in the wild beyond the malspam distribution. The lack of affected versions or patch information suggests this is not a vulnerability in software but rather a malware distribution campaign relying on user interaction to execute the malicious script.

For European organizations, the primary impact of this malspam campaign lies in the potential compromise of endpoint systems if users execute the malicious JavaScript files. Successful execution could lead to unauthorized access, data theft, or the installation of additional malware, potentially disrupting business operations or leading to data breaches. Given the social engineering theme of "suspected purchases," finance and procurement departments may be particularly targeted or vulnerable. While the campaign is rated low severity and does not indicate widespread exploitation, organizations with less mature email filtering or user awareness programs could be at risk. The impact is mostly confined to confidentiality and integrity of affected systems, with availability impact being less likely unless the malware includes destructive payloads. Since the campaign requires user interaction (opening the attachment and executing the script), the risk can be mitigated with proper user training and technical controls.

To mitigate this threat, European organizations should implement advanced email filtering solutions capable of detecting and quarantining suspicious ZIP attachments containing JavaScript files. Endpoint protection platforms should be configured to block or alert on execution of scripts from email attachments or temporary directories. User awareness training should emphasize the risks of opening unexpected attachments, especially those referencing financial transactions or purchases. Organizations should enforce policies to disable execution of JavaScript files from email attachments and consider application whitelisting to prevent unauthorized script execution. Regular updates to antivirus and endpoint detection and response (EDR) tools are essential to detect evolving malware variants. Additionally, network monitoring for unusual outbound connections can help identify compromised hosts. Incident response plans should include procedures for malspam campaigns to quickly isolate and remediate infected systems.