This threat involves a malspam campaign identified on August 23, 2016, distributing malware via email attachments. The campaign uses social engineering by sending emails with the subject line "New voice mail message from [RANDOM]" to entice recipients to open the attachment. The attachment is a .zip file containing a .wsf (Windows Script File), which is a script file that can execute code on Windows systems. When the user extracts and runs the .wsf file, it can execute malicious scripts, potentially leading to system compromise. The use of .wsf files is notable because they can contain complex scripts and are less commonly blocked by some email filters compared to executable files, increasing the likelihood of successful delivery and execution. The campaign's low severity rating and lack of known exploits in the wild suggest limited impact or scope, possibly due to effective detection or limited distribution. However, the threat remains relevant as it demonstrates common tactics used in malware distribution: leveraging social engineering, compressed archives to bypass filters, and script-based payloads to execute malicious code.

For European organizations, this malspam campaign poses a risk primarily through user interaction—opening the attachment and executing the script. If successful, it could lead to unauthorized code execution, potentially compromising confidentiality, integrity, and availability of affected systems. The impact could include data theft, installation of additional malware, or use of the compromised system as a foothold for lateral movement within networks. Although the campaign is rated low severity and no widespread exploitation is reported, organizations with less mature email filtering or user awareness programs could be vulnerable. The threat is particularly concerning for sectors with high email usage and reliance on Windows environments, such as finance, government, and critical infrastructure. The social engineering aspect exploits human factors, which remain a significant vector for malware delivery in Europe.

To mitigate this threat, European organizations should implement advanced email filtering solutions that specifically scan compressed archives and script files for malicious content. Blocking or quarantining emails containing .wsf files or .zip archives with script files can reduce risk. User awareness training should emphasize the dangers of opening unexpected attachments, especially those purporting to be voice mail notifications or similar social engineering lures. Endpoint protection solutions should be configured to detect and block script-based malware execution. Organizations can also implement application whitelisting to prevent unauthorized script execution and restrict execution of .wsf files to trusted users or systems only. Regular patching of Windows systems and disabling Windows Script Host where not needed can further reduce attack surface. Monitoring email traffic and endpoint behavior for indicators of compromise related to script execution is recommended for early detection.