The provided information describes a malspam campaign dated May 26, 2016, distributing the Locky ransomware. Locky is a type of ransomware malware that encrypts victims' files and demands payment for decryption. The samples analyzed in this campaign were noted to be obfuscated using techniques such as reversing the binary and applying XOR operations with keys (0x73, 0x1c, or a longer XOR key). These obfuscation methods are intended to evade detection by antivirus and security tools. The campaign involved sending malicious spam emails (malspam) containing these Locky payloads. Although the exact infection vector is not detailed, Locky typically spreads through email attachments or links that, when executed, download and run the ransomware. The technical details indicate a low severity rating and no known exploits in the wild beyond the malspam distribution. The threat level is moderate (3 out of an unspecified scale), with no further analysis or indicators provided. Locky ransomware is known for encrypting a wide range of file types, causing data loss and operational disruption if not mitigated promptly.

For European organizations, the impact of Locky ransomware can be significant despite the low severity rating in this specific report. Successful infections can lead to widespread encryption of critical business data, resulting in operational downtime, financial losses due to ransom payments or recovery costs, and potential reputational damage. Sectors with high data sensitivity such as healthcare, finance, and government are particularly vulnerable. The malspam vector means that organizations with insufficient email filtering or user awareness are at higher risk. Additionally, the obfuscation techniques used in this campaign could reduce the effectiveness of traditional signature-based detection, increasing the likelihood of successful infection. While the campaign dates back to 2016, variants of Locky and similar ransomware continue to pose threats, emphasizing the need for ongoing vigilance.

To mitigate the risk posed by Locky ransomware and similar malspam campaigns, European organizations should implement multi-layered defenses beyond generic advice: 1) Deploy advanced email filtering solutions that use heuristic and behavior-based detection to identify obfuscated malware payloads. 2) Conduct regular user training focused on recognizing phishing and malspam tactics, emphasizing caution with unsolicited attachments and links. 3) Maintain up-to-date endpoint protection platforms capable of detecting ransomware behavior, including monitoring for file encryption activities. 4) Implement network segmentation to limit ransomware spread if infection occurs. 5) Regularly back up critical data using the 3-2-1 rule (three copies, two different media, one offsite) and verify backup integrity to enable recovery without paying ransom. 6) Employ application whitelisting to prevent execution of unauthorized binaries, including those that may be obfuscated. 7) Monitor network traffic for unusual patterns indicative of ransomware communication or propagation. 8) Keep all systems and software patched to reduce attack surface, even though no specific exploits are noted here.