This threat report concerns malspam campaigns from March 14, 2016, distributing ransomware families Locky and TeslaCrypt. Malspam refers to malicious spam emails that deliver malware payloads to victims. Locky and TeslaCrypt are ransomware variants that encrypt victims' files and demand ransom payments for decryption keys. Locky ransomware emerged in early 2016 and was notable for its widespread distribution via spam emails containing malicious attachments or links. TeslaCrypt similarly targeted users with ransomware that encrypted files, particularly those related to gaming, before evolving into other malware forms. The malspam campaigns typically used social engineering tactics to trick users into opening infected attachments or clicking on malicious URLs, leading to ransomware infection. The technical details provided are minimal, indicating a low threat level and no known exploits in the wild beyond the spam distribution method. No specific affected software versions or patches are noted, as the infection vector is primarily user interaction with malicious email content. The threat level of 3 (on an unspecified scale) and low severity rating reflect the dated nature of this campaign and the general ransomware infection vector. However, ransomware remains a significant threat due to its impact on data confidentiality and availability. This report serves as a historical reference to the Locky and TeslaCrypt ransomware campaigns distributed via malspam in 2016.

For European organizations, ransomware infections like Locky and TeslaCrypt can lead to severe operational disruptions by encrypting critical data and demanding ransom payments. The impact includes loss of data confidentiality and availability, potential financial losses from ransom payments or downtime, reputational damage, and regulatory consequences under GDPR if personal data is affected. Although this specific campaign is from 2016 and rated low severity, ransomware remains a persistent threat in Europe due to the high reliance on digital infrastructure. Organizations in sectors such as healthcare, finance, government, and critical infrastructure are particularly vulnerable to ransomware impacts. The malspam delivery method exploits human factors, making phishing awareness and email security crucial. The absence of known exploits in software suggests that the primary risk is user interaction leading to infection rather than technical vulnerabilities in software products.

To mitigate ransomware threats like Locky and TeslaCrypt, European organizations should implement multi-layered defenses beyond generic advice: 1) Deploy advanced email filtering solutions that use machine learning and threat intelligence to detect and quarantine malspam with ransomware payloads. 2) Conduct regular, targeted phishing simulation exercises and security awareness training focused on recognizing malicious attachments and links. 3) Implement application whitelisting to prevent execution of unauthorized programs, including ransomware executables. 4) Maintain robust, offline, and immutable backups of critical data to enable recovery without paying ransom. 5) Use endpoint detection and response (EDR) tools to identify and isolate ransomware activity early. 6) Enforce strict least privilege access controls to limit ransomware propagation. 7) Keep all systems and security tools updated to defend against newer ransomware variants. 8) Establish incident response plans specific to ransomware scenarios, including communication and legal considerations under GDPR. These measures collectively reduce the risk of infection and limit damage if ransomware is executed.