The threat described pertains to a variant of the Locky ransomware family, identified in November 2017. Locky ransomware is a type of malicious software that encrypts victims' files and demands a ransom payment for the decryption key. This particular instance is referenced with an offline affiliation ID (Affid=3) and a file extension ".asasin" associated with encrypted files, exemplified by the filename "12345678.doc". The ransomware typically spreads via phishing emails containing malicious attachments or links, which when executed, initiate the encryption process. Locky is known for targeting a wide range of file types, including documents, images, and databases, rendering them inaccessible to users. The technical details indicate a low threat level (3 on an unspecified scale) and a low severity rating, with no known exploits in the wild at the time of reporting. The absence of affected versions and patch links suggests this is a generic detection or a sample rather than a newly discovered vulnerability in a specific product. The ransomware operates by encrypting files locally on the infected system, often renaming them with unique extensions such as ".asasin" to mark encrypted files. The offline designation implies that this variant may not rely on communication with a command-and-control server during the encryption process, potentially making it harder to disrupt via network-based interventions. Overall, this Locky variant represents a typical ransomware threat from 2017, with standard infection and encryption mechanisms but no novel exploitation vectors or vulnerabilities disclosed in this report.

For European organizations, the impact of this Locky ransomware variant primarily involves the loss of access to critical data due to file encryption. This can disrupt business operations, cause financial losses, and damage organizational reputation. Since Locky targets a broad spectrum of file types, organizations with extensive document repositories, such as legal firms, healthcare providers, financial institutions, and public sector entities, are at particular risk. The offline nature of this variant means that traditional network-based detection and mitigation strategies might be less effective, potentially allowing the ransomware to encrypt files before detection. Although the reported severity is low, the actual impact depends on the organization's backup and recovery capabilities. Organizations lacking robust, isolated backups or incident response plans may face prolonged downtime and costly recovery efforts. Additionally, the ransomware's presence can lead to secondary impacts such as regulatory non-compliance, especially under GDPR, if personal data is affected and not recoverable. The threat does not appear to exploit specific software vulnerabilities but relies on social engineering and user interaction, which means that human factors remain a critical risk vector.

1. Implement advanced email filtering and sandboxing solutions to detect and block phishing emails containing malicious attachments or links, focusing on indicators associated with Locky ransomware campaigns from the 2017 period. 2. Conduct regular, targeted user awareness training emphasizing the risks of opening unsolicited attachments or clicking unknown links, with simulated phishing exercises to reinforce vigilance. 3. Maintain comprehensive, offline, and immutable backups of critical data to ensure rapid restoration without paying ransom; verify backup integrity regularly. 4. Deploy endpoint detection and response (EDR) tools capable of identifying ransomware behaviors such as rapid file encryption and unusual file renaming patterns (e.g., ".asasin" extensions). 5. Enforce strict application whitelisting and least privilege principles to limit execution of unauthorized software and reduce the attack surface. 6. Monitor network traffic for anomalies that may indicate ransomware activity, even if this variant operates offline, to detect lateral movement or other suspicious behaviors. 7. Develop and regularly update an incident response plan specifically addressing ransomware scenarios, including containment, eradication, and recovery procedures. 8. Ensure all systems and software are kept up to date with security patches to reduce the risk of exploitation by other malware that could facilitate ransomware delivery. 9. Segment networks to contain infections and prevent spread to critical systems. 10. Collaborate with national cybersecurity centers and share threat intelligence to stay informed about emerging ransomware variants and mitigation strategies.