Ransomware in 2025: Lessons from Locky and Modern Defense Strategies

In 2024, ransomware attacks have become increasingly sophisticated, with groups like LockBit leading the charge. A significant attack in May targeted Canadian retail chain London Drugs, causing operational disruptions and raising concerns about stolen customer data. LockBit’s use of advanced encryption and data exfiltration tactics underscores the growing vulnerability of retail businesses to such threats.

In this blog, we’ll explore what makes ransomware like Locky and similar strains so dangerous, how these attacks work, and how your organization can implement effective defenses.

What is Locky Ransomware?

Locky is a notorious ransomware strain that emerged with the capability to encrypt files on both local drives and unmapped network shares. It gained infamy for its ability to render critical data inaccessible by altering filenames, further complicating recovery efforts. Locky’s impact on businesses worldwide has been significant, causing financial and reputational damage to unprepared organizations.

How the Locky Attack Works

Locky typically enters systems via phishing emails designed to appear credible and urgent. These emails often feature subject lines like “ATTN: Invoice J-98223146”, prompting users to open an attached Word document. Upon opening, the document displays scrambled content and urges users to enable macros, a seemingly harmless action that unleashes the ransomware.

Once enabled, the macro downloads a malicious executable file to the %Temp% folder, initiating the ransomware’s encryption process. Locky encrypts a wide range of file types, renames them with unique extensions, and locks users out of their own data.

Social Engineering Tactics Used

The success of Locky ransomware relies heavily on its clever use of social engineering to manipulate users. Common tactics include:

• Urgency: Attackers craft emails to create a sense of immediate action, such as addressing unpaid invoices or urgent requests.

• Familiarity: Messages are designed to mimic legitimate business communications, increasing their trustworthiness.

Why Locky is a Significant Threat

Locky’s ability to encrypt files on network shares, including unmapped ones, significantly amplifies its damage potential. Additionally, its practice of renaming files during encryption adds an extra layer of complexity to recovery efforts.

What makes Locky particularly challenging is the absence of reliable public decryption tools, leaving victims with limited options: pay the ransom or face potential data loss. This underscores the importance of robust preventative measures to counter such attacks.

Recommended Defensive Measures

Organizations can adopt a multi-layered approach to protect against ransomware like Locky:

• Backup and Restore Procedures

Regularly maintain offline backups to ensure rapid recovery without paying a ransom.

• Macro Security Settings

Configure Microsoft Office settings to disable all macros except digitally signed ones, minimizing a key infection vector.

• Establish Trusted Locations

Restrict macros to run only from trusted sources, reducing exposure to malicious files.

• Security Awareness Training

Educate employees to recognize phishing tactics and understand the risks of enabling macros. Access resources like Keepnet Security Awareness Training.

• Endpoint Protection Tools

Deploy Endpoint Detection and Response (EDR) solutions to detect and block ransomware before it can encrypt files.

For a comprehensive approach to resilience, consider tools like the Keepnet Human Risk Management Platform.

How to Implement Macro Security Policies

To fortify defenses against macro-based attacks, IT administrators should:

1. Open the Trust Center in Microsoft Office.
2. Adjust settings under Macro Settings to disable all macros except digitally signed ones.
3. Regularly update trusted locations to ensure only verified sources are permitted.

Following these steps minimizes risks from malicious macros. Test your organization’s readiness with our Phishing Simulator.

The Importance of Security Awareness Training

Human error is a critical factor in successful ransomware attacks. Security awareness training equips employees to identify phishing attempts and avoid enabling malicious macros.

Regular phishing simulations can highlight gaps in employee awareness and provide insights for tailored training. Organizations that invest in this proactive approach report significantly fewer incidents of successful attacks.

Learn how to enhance your workforce’s resilience with our Security Awareness Training.

Keepnet Human Risk Management Platform

Combat ransomware threats like Locky with the Keepnet Human Risk Management Platform. This integrated solution offers:

• Phishing Simulators to test and train employees against phishing attacks.
• Security Awareness Training tailored to specific organizational needs.
• Incident Responder to streamline the detection, reporting, and mitigation of suspicious activities.

Empower your organization to stay ahead of emerging threats by auditing your macro security policies and fostering a vigilant workforce.