In the ever-evolving landscape of cybersecurity threats, ransomware has emerged as a particularly insidious form of malicious software, causing havoc for individuals, businesses, and even governments.
One particularly notorious strain is known as Locky ransomware. First appearing in early 2016, Locky has hit organizations and individuals across the globe, encrypting files and demanding ransom payments in Bitcoin to decrypt them.
This article aims to provide a comprehensive understanding of Locky Ransomware, delving into its origins, modes of operation and impact on victims.
Contents
What is Locky Ransomware?
Locky is a type of crypto-ransomware, meaning it encrypts files on infected systems and renders them inaccessible to the user. The encryption used by Locky is robust, making it nearly impossible for victims to recover encrypted files without the decryption key.
Locky is spread through spam email campaigns that distribute the malware as attachments, often masquerading as invoices, receipts or other business documents. If the attachment is opened, Locky is downloaded onto the victim’s computer where it encrypts a wide range of file types, including documents, images, audio files and videos.
Once encryption is complete, Locky displays a ransom note informing the victim that files are locked and demanding a ransom payment in Bitcoin to receive the decryption key. The ransom amount usually ranges from 0.5 to 2 Bitcoin, though some victims have been extorted for up to 10 Bitcoin. Payment instructions are provided along with threats that files will be permanently lost if the ransom is not paid.
The emails distributing Locky are carefully crafted to appear legitimate and originates from spoofed or compromised business accounts. This allows the ransomware to evade traditional email security defenses. Locky is also spread through exploit kits hosted on malicious websites that can detect and exploit vulnerabilities in browsers and plugins to silently download the malware.
Modes of Operation
Locky employs advanced encryption algorithms, commonly utilizing RSA-2048 and AES-128 encryption methods. This renders the victim’s files inaccessible without the corresponding decryption key, which the attackers withhold until a ransom is paid. The encrypted files often include crucial documents, images, and other sensitive data, crippling the victim’s ability to function.
Locky is also known for its ability to spread across networks, encrypting files not only on the infected device but also on connected servers and devices within the same network. This makes it particularly threatening for businesses and organizations with interconnected systems.
Locky Ransomware Working
Once executed on the victim’s machine, Locky initiates an intricate multi-stage process to infect the system and encrypt files. These steps include:
- Connecting to command and control (C&C) servers controlled by the hackers to download the encryption modules. This communication is done using obfuscated protocols to avoid detection by security tools.
- Using built-in Windows tools like Powershell for propagation on the infected system and network shares. Locky disables Windows Update and other protection mechanisms.
- Searching for and encrypting hundreds of local file types with strong encryption (AES and RSA) to restrict access. The encryption keys are uniquely generated on each infected host and transmitted to the C&C servers.
- Changing the wallpaper and appending every encrypted file with .locky extension along with a unique ID. The encrypted files cannot be easily identified just by the extension.
- Once encryption is complete, the ransom note is displayed prominently demanding payment for decryption. A countdown timer is also shown threatening permanent loss of files.
Impact on Victims
The impact of Locky Ransomware on its victims is multifaceted. Beyond the immediate loss of access to critical files, the psychological and financial toll on individuals and organizations can be substantial. Victims are faced with the difficult decision of whether to pay the ransom, which is usually demanded in cryptocurrencies like Bitcoin, or attempt to recover their files through other means.
Even if the ransom is paid, there is no guarantee that the attackers will provide a working decryption key. Furthermore, succumbing to the demands of cybercriminals only fuels the proliferation of ransomware attacks, as it proves to be a lucrative business for perpetrators.
Locky Ransomware High-Profile Victims
In 2016 When the Hollywood Presbyterian Medical Center was hit by Locky Ransomware, administrators ended up paying over $17,000 in Bitcoin to regain access to encrypted patient records, medical scans and other files.
Other high-profile victims include a police department in Massachusetts that paid a $500 ransom and a newspaper company in California that paid over $17,000. Individual victims without backups of their personal files often find themselves with no option but to pay the ransom or lose their data.
Conclusion
Locky Ransomware stands as a stark reminder of the ever-present threat landscape in the digital realm. As technology advances, so too do the tactics employed by cybercriminals. Understanding the intricacies of threats like Locky is essential for individuals and organizations to fortify their defenses and mitigate potential risks. By combining user education, advanced security measures, and proactive strategies, we can collectively work towards creating a more resilient digital environment.