The provided information describes a malware threat identified as "Locky" ransomware, specifically a variant or campaign dated 2017-09-26. Locky ransomware is a well-known strain of malicious software that encrypts victims' files and demands ransom payments for decryption keys. This particular instance is tagged with indicators such as ".ykcol":"INVOICE" and a file name pattern "A1234567890.7z", suggesting that the ransomware may be distributed via email attachments masquerading as invoices compressed in 7z archives. The mention of "Affid=3, offline" likely refers to an internal tracking or classification system, indicating an offline or isolated sample with a threat level of 3 (on an unspecified scale). The ransomware operates by encrypting user data, rendering it inaccessible, and then prompting victims to pay a ransom, typically in cryptocurrency. While the severity is marked as low, Locky historically has caused significant disruption due to its widespread distribution and effective encryption mechanisms. No specific affected versions or patches are listed, and no known exploits in the wild are reported for this sample, suggesting it may be an older or less active variant. The technical details are minimal, but the classification as ransomware and the presence of typical ransomware indicators confirm its malicious nature.

For European organizations, Locky ransomware poses a risk primarily through email phishing campaigns that deliver malicious attachments. If successful, the ransomware can encrypt critical business data, leading to operational downtime, loss of data integrity, and potential financial losses due to ransom payments or recovery costs. Although this specific variant is marked with low severity and no known active exploits, the general Locky ransomware family has historically affected various sectors including healthcare, finance, and public administration in Europe. The impact includes disruption of services, reputational damage, and potential regulatory consequences under GDPR if personal data is compromised or lost. Organizations with inadequate email filtering, outdated endpoint protection, or insufficient user awareness are particularly vulnerable. The offline designation suggests this sample may not be currently active, but the threat remains relevant as similar ransomware campaigns continue to target European entities.

To mitigate the risk posed by Locky ransomware and similar threats, European organizations should implement multi-layered defenses beyond generic advice: 1) Deploy advanced email filtering solutions capable of detecting and quarantining suspicious compressed attachments, especially those with uncommon extensions like .7z. 2) Enforce strict attachment handling policies, including blocking or sandboxing of executable or archive files received via email. 3) Conduct targeted user awareness training focused on recognizing phishing emails that impersonate invoices or financial documents. 4) Maintain regular, tested offline backups of critical data to enable recovery without paying ransom. 5) Utilize endpoint detection and response (EDR) tools that can identify ransomware behavior patterns early and isolate infected systems. 6) Implement application whitelisting to prevent unauthorized execution of unknown binaries. 7) Monitor network traffic for unusual outbound connections that may indicate ransomware communication with command and control servers. 8) Keep all systems and security software up to date to reduce exposure to known vulnerabilities that ransomware might exploit as a secondary infection vector.