The threat described pertains to a variant of the Locky ransomware, identified as "M2M - Locky Affid=3, '.asasin'" active around November 1, 2017. Locky ransomware is a well-known malware family that encrypts victims' files and demands ransom payments for decryption keys. This specific variant appears to propagate via email campaigns, as indicated by the reference to an email subject and attachment naming convention: "Emailing: AZ123 - 01.11.2017" with an attached document named "AZ123 - 01.11.2017.doc". The use of a .doc file suggests that the infection vector relies on malicious Microsoft Word documents, likely containing macros or embedded scripts that execute the ransomware payload once the document is opened and macros are enabled. The technical details classify the threat level as 3 (on an unspecified scale) and the severity as low, with no known exploits in the wild beyond the email distribution method. The absence of affected product versions and patch links indicates this is a malware campaign rather than a vulnerability in a specific software product. Locky ransomware typically encrypts a wide range of file types, impacting confidentiality and availability by denying access to data. The campaign's naming and timing suggest a targeted or mass phishing operation using social engineering to trick users into opening malicious attachments. Given the nature of Locky ransomware, infection leads to file encryption and ransom demands, often payable in cryptocurrencies, with no guaranteed recovery of data without backups or decryption tools. The campaign's reliance on email and document macros highlights the importance of user awareness and endpoint protections.

For European organizations, the impact of this Locky ransomware variant can be significant, particularly for entities with limited cybersecurity maturity or inadequate email filtering and endpoint protection. The ransomware compromises data availability by encrypting critical files, potentially disrupting business operations, causing financial losses, and damaging reputations. Sectors with high reliance on data integrity and availability, such as healthcare, finance, manufacturing, and public administration, are particularly vulnerable. The low severity rating suggests this variant may have limited sophistication or reach compared to other ransomware strains; however, even low-severity ransomware can cause operational disruptions if successful. The email-based infection vector exploits human factors, making organizations with insufficient user training or weak email security controls more susceptible. Additionally, the lack of known exploits in the wild beyond phishing means the threat is primarily opportunistic rather than targeted, but widespread campaigns can still affect multiple European organizations. Recovery costs include incident response, potential ransom payments, data restoration, and reputational damage. The threat also underscores the ongoing risk posed by macro-enabled documents as an infection vector in Europe, where email remains a primary communication tool.

To mitigate this Locky ransomware threat, European organizations should implement several specific measures beyond generic advice: 1) Enforce strict email filtering policies that block or quarantine emails with suspicious attachments, especially macro-enabled Office documents (.doc, .docm). 2) Disable macros by default in Microsoft Office applications and only allow macros from trusted sources, using Group Policy or Office configuration settings. 3) Deploy advanced endpoint protection solutions with behavioral detection capabilities to identify and block ransomware execution and encryption activities. 4) Conduct regular, targeted user awareness training focused on phishing recognition and the risks of enabling macros in unsolicited documents. 5) Implement network segmentation and least privilege principles to limit ransomware propagation if a device is infected. 6) Maintain up-to-date, tested offline backups of critical data to enable recovery without paying ransom. 7) Monitor email traffic and endpoint logs for indicators of compromise related to Locky campaigns, such as unusual document attachments or execution of suspicious scripts. 8) Employ application whitelisting to prevent unauthorized execution of ransomware payloads. 9) Collaborate with national Computer Security Incident Response Teams (CSIRTs) for threat intelligence sharing and incident response support. These targeted controls address the specific infection vector and ransomware behavior observed in this Locky variant.