SORVEPOTEL is a malware strain observed spreading on Windows systems through phishing emails containing malicious ZIP file attachments. The phishing lure is crafted to entice users to open the attachment on desktop environments, suggesting that attackers aim at enterprise users rather than casual consumers. Upon execution, the malware uses PowerShell scripts and loader components to establish persistence and execute payloads. It then propagates via WhatsApp Web by automatically sending spam messages to contacts, which results in infected WhatsApp accounts being banned due to spam detection. The malware's propagation via WhatsApp Web is notable because it leverages a widely used communication platform to spread laterally and potentially infect other users. The infection chain involves social engineering, script execution, and abuse of legitimate communication channels. Although initially reported in Brazil, the techniques used could be adapted to other regions where WhatsApp Web is prevalent. The malware employs various tactics such as code injection (T1055), command and scripting interpreter abuse (T1059), persistence mechanisms (T1547), and credential access techniques (T1550). No known exploits beyond phishing delivery are reported, and no CVSS score is assigned. The malware's impact includes potential disruption of business communications, account bans, and the risk of further spreading within enterprise environments.

For European organizations, the primary impact of SORVEPOTEL lies in the disruption of business communications via WhatsApp Web, which is widely used for internal and external communications in many enterprises. Infected accounts being banned can cause operational interruptions and reputational damage. The malware's ability to propagate through social engineering and abuse of legitimate platforms increases the risk of lateral spread within organizations, potentially leading to broader compromise. Enterprises with business relations or communication channels involving Brazilian partners or customers may face higher exposure. Additionally, the use of PowerShell and loader techniques can facilitate further payload delivery or data exfiltration if combined with other malware components. The phishing vector also poses risks of credential theft or further infection. Although the malware currently targets Brazilian users, European organizations with WhatsApp Web usage should consider the threat relevant due to the global nature of the platform and potential for adaptation by threat actors. The medium severity reflects moderate impact with limited scope but notable operational disruption and propagation risk.

1. Implement advanced email filtering to detect and block phishing emails containing malicious ZIP attachments, focusing on indicators such as suspicious sender domains and attachment anomalies. 2. Conduct targeted user awareness training emphasizing the risks of opening unexpected attachments, especially on desktop environments, and recognizing phishing attempts. 3. Restrict or monitor the use of WhatsApp Web within enterprise environments, including the use of endpoint security solutions to detect abnormal WhatsApp Web activity or automated messaging. 4. Deploy application control policies to prevent unauthorized execution of PowerShell scripts or suspicious loader binaries, using whitelisting where feasible. 5. Enable logging and monitoring of PowerShell usage and command-line activities to detect potential abuse indicative of malware execution. 6. Regularly update endpoint detection and response (EDR) tools to identify behaviors associated with SORVEPOTEL, such as persistence mechanisms and lateral propagation attempts. 7. Encourage multi-factor authentication (MFA) on WhatsApp accounts to reduce the risk of account takeover. 8. Collaborate with communication platform providers to understand and mitigate abuse vectors related to automated messaging. 9. Maintain incident response plans that include procedures for handling compromised communication accounts and rapid containment of malware spread. 10. For organizations with Brazilian connections, increase vigilance and threat intelligence sharing to detect early signs of infection.