The provided information pertains to a variant of the Locky ransomware identified on 2017-09-29, referenced as "M2M - Locky 2017-09-29 : Affid=3, offline, ".ykcol" : "Invoice" - "123456.7z"." Locky ransomware is a well-known malware family that encrypts user files and demands ransom payments for decryption keys. This specific variant appears to use the file extension ".ykcol" for encrypted files, which is "locky" reversed, and is associated with files named like "Invoice" and archives such as "123456.7z". The mention of "offline" suggests that this variant may operate without requiring immediate communication with a command and control server, possibly using offline encryption keys. The ransomware typically spreads via malicious email attachments or links, often disguised as invoices or other business-related documents, which aligns with the "Invoice" keyword in the description. The threat level is indicated as 3 (on an unspecified scale), and the severity is marked as low, with no known exploits in the wild at the time of reporting. No specific affected product versions or patches are listed, indicating this is a malware threat rather than a software vulnerability. The lack of indicators and detailed technical data limits deeper analysis, but the core behavior aligns with typical Locky ransomware operations: encrypting files and demanding ransom, potentially disrupting business operations.

For European organizations, the impact of this Locky ransomware variant could include data encryption leading to loss of access to critical business files, operational disruption, and potential financial loss due to ransom payments or recovery costs. The use of invoice-themed filenames suggests targeting of financial or accounting departments, which could amplify operational impact. Although the severity is marked as low and no active exploits were reported at the time, ransomware infections can escalate quickly if not contained. European organizations with less mature email filtering, endpoint protection, or user awareness training are at higher risk. Additionally, offline encryption capabilities mean that even isolated systems could be affected without network communication, complicating detection and response. The impact on confidentiality is limited as ransomware primarily affects availability and integrity of data. However, operational continuity and data integrity are significantly threatened, potentially affecting compliance with data protection regulations such as GDPR if backups or recovery processes are inadequate.

To mitigate this threat, European organizations should implement targeted email security controls to detect and block malicious attachments, especially those disguised as invoices or compressed archives (.7z files). User awareness training should emphasize caution with unsolicited emails and attachments. Endpoint protection solutions with behavioral detection capabilities can help identify ransomware activity, including offline encryption attempts. Regular, tested backups stored offline or in immutable storage are critical to recovery without paying ransom. Network segmentation can limit ransomware spread if infection occurs. Incident response plans should include ransomware-specific procedures. Since this variant may operate offline, monitoring for unusual file extensions like ".ykcol" and sudden mass file encryption events is important. Organizations should also ensure that all systems are patched and up to date to reduce attack surface, even though no specific vulnerabilities are noted here. Finally, sharing threat intelligence within European cybersecurity communities can enhance early detection and response.