What is Ransomware and How to Defend Against It

What is Ransomware?

Ransomware is a type of malicious software that encrypts the victim’s files, rendering them inaccessible until a ransom is paid to the attackers. The rise of ransomware has made it one of the most disruptive forms of cybercrime. Unlike other forms of malware, ransomware is particularly dangerous because it not only infiltrates into your system but also holds your sensitive data hostage, putting both your operations and reputation at risk.

Cybercriminals often demand payment in cryptocurrencies like Bitcoin, which provides them with a level of anonymity. The ransom amount can vary, but the impact of the attack is typically severe, leading to significant downtime, financial loss, and, in some cases, permanent data loss.

History of Ransomware Attacks

The concept of ransomware dates back to the late 1980s. The first known ransomware attack occurred in 1989, known as the “AIDS Trojan” or “PC Cyborg” ransomware. It was distributed via floppy disks and demanded a payment of $189 to be sent to a P.O. box in Panama to unlock the infected files. This rudimentary form of ransomware laid the groundwork for more sophisticated attacks that would emerge in the following decades.

Ransomware started gaining significant traction in the early 2010s with the rise of crypto-ransomware, where files are encrypted and only a decryption key can unlock them. The infamous “CryptoLocker” ransomware, which surfaced in 2013, marked a turning point in the evolution of ransomware. It spread through phishing emails and encrypted a wide range of file types, demanding payment in Bitcoin. This attack introduced the now-common practice of demanding cryptocurrency as ransom, making it harder to trace the cybercriminals involved.

Since then, ransomware attacks have become increasingly frequent and more sophisticated. High-profile incidents like the WannaCry attack in 2017, which affected over 200,000 computers across 150 countries, and the NotPetya attack, which caused widespread disruption in Ukraine before spreading globally, have highlighted the significant threat ransomware poses.

Examples of Ransomware

Over the years, several ransomware strains have become notorious for their widespread impact:

1. CryptoLocker: One of the first ransomware strains to gain notoriety, CryptoLocker spread via phishing emails and demanded Bitcoin for decryption.
2. WannaCry: A global ransomware attack that exploited the EternalBlue vulnerability in Microsoft Windows, rapidly spreading across the networks worldwide. Wannacry affected over 200,000 systems and demanded Bitcoin payments for decryption.
3. Petya/NotPetya: Initially, Petya was a typical ransomware, but the NotPetya variant turned out to be a wiper, destroying data under the guise of ransomware, and causing massive losses globally.
4. Ryuk: Known for targeting large enterprises, Ryuk has been used in sophisticated attacks that often involve high ransom demands.
5. Maze: Not only did Maze encrypt data, but it also exfiltrated it, threatening to release sensitive information unless the ransom was paid, setting a trend for double extortion.
6. REvil (Sodinokibi): A ransomware-as-a-service (RaaS) operation, REvil has been responsible for numerous high-profile attacks, often demanding millions in ransom.

How Does Ransomware Work

Ransomware typically follows a series of steps from initial infection to encryption of files, ultimately demanding payment from the victim. Here’s a more detailed breakdown of the process:

1. Initial Infection: Ransomware often infiltrates a system through phishing emails, malicious links, or compromised websites. Once the victim interacts with the malicious content, such as clicking a link or downloading an attachment, the ransomware is deployed on the system.
2. Establishing Persistence: After gaining access, the ransomware installs itself and often modifies system settings to ensure it runs every time the system starts. Some variants may even disable antivirus software and security features to avoid detection.
3. Communication with Command and Control (C&C) Server: The ransomware connects to a remote command and control server operated by the attackers. This connection allows the ransomware to receive encryption keys and further instructions, while also reporting back on the status of the infection.
4. File Scanning and Encryption: Once established, the ransomware begins scanning the system and network drives for files to encrypt. It targets commonly used file types, like documents, images, and databases, ensuring maximum impact. The ransomware uses advanced encryption algorithms to lock the files, making them inaccessible to the victim.
5. Ransom Demand: After encryption, a ransom note is displayed, often on the desktop or in each affected folder. This note typically demands payment in cryptocurrency, such as Bitcoin, in exchange for the decryption key. The attackers may also threaten to publish or destroy the data if the ransom is not paid within a specified timeframe.
6. Data Exfiltration (Optional): In some cases, before encrypting the files, the ransomware might exfiltrate sensitive data to the attackers’ servers. This data is then used as leverage in what is known as a “double extortion” attack, where the victim is threatened with public exposure of their data if the ransom isn’t paid.
7. Final Outcome: If the ransom is paid, the attackers may—or may not—provide a decryption key. However, paying the ransom does not guarantee that the data will be restored, nor does it prevent future attacks. If the ransom is not paid, the victim might attempt to restore their data from backups, provided they have secure and recent backups in place.

How Does Ransomware Spread

Ransomware spreads through several common vectors, each exploiting vulnerabilities or human error:

Phishing Emails: The most common method of ransomware distribution, phishing emails trick users into clicking on malicious links or downloading infected attachments.

Drive-By Downloads: Users can unknowingly download ransomware by visiting compromised websites, which exploit browser vulnerabilities to deliver the malware.

Remote Desktop Protocol (RDP): RDP is frequently exploited by ransomware attackers to gain unauthorized access to a network. Weak or compromised RDP credentials are a common entry point for ransomware.

Malvertising: Malicious advertisements can redirect users to compromised websites where ransomware is downloaded automatically. Even legitimate websites can host malvertising if they display ads from compromised ad networks.

USB Drives: Physical media, such as USB drives, can also spread ransomware. When an infected drive is plugged into a computer, the ransomware is automatically executed, spreading to the system.

How to Detect Ransomware

Detecting ransomware early is crucial to minimizing its impact. Several methods can help detect ransomware before it causes significant damage:

Behavioral Analysis: Monitoring the behavior of files and applications for signs of ransomware activity, such as rapid file encryption or unusual network communication, can help detect new or unknown ransomware variants.

Signature-Based Detection: Antivirus and anti-malware solutions use signature-based detection to identify known ransomware variants. However, this method may struggle with new or modified strains.

Heuristic Analysis: Heuristic analysis examines the characteristics and behavior of files to identify possible threats. This approach can detect ransomware by analyzing patterns that resemble known malicious behavior.

Deception Technology: Deception techniques, such as deploying honeypots or decoy systems, can lure ransomware into attacking a controlled environment. This allows security teams to detect and analyze the ransomware without risking real data.

Endpoint Detection and Response (EDR): The EDR solution monitors endpoints for suspicious activities and provides real-time alerts, enabling rapid response to ransomware attacks.

How to Defend Against Ransomware

Effective defense against ransomware requires a combination of proactive measures and effective security practices:

Regular Backups: Maintain regular, offline backups of all critical data. Ensure backups are tested for integrity and can be restored quickly in case of an attack. Offline or air-gapped backups are crucial to avoid ransomware encrypting backup files.

Security Awareness Training: Educate employees about the dangers of phishing and social engineering attacks. Regular training helps prevent users from inadvertently introducing ransomware into the network.

Patch Management: Regularly update and patch software and systems to close vulnerabilities that ransomware may exploit. Timely application of security patches is essential for protecting against known threats.

Network Segmentation: Implement network segmentation to isolate critical systems and limit the spread of ransomware. Segmentation helps contain an attack and protect essential assets from being compromised.

Access Control: Enforce strict access controls and limit administrative privileges. Ensure that only authorized personnel can access sensitive data and systems to reduce the risk of ransomware spreading.

Incident Response Plan: Develop and maintain a comprehensive incident response plan outlining the steps to take in the event of a ransomware attack. Regularly test and update the plan to ensure readiness and effectiveness.

Multi-Factor Authentication (MFA): Implement MFA to provide an additional layer of security. MFA helps protect against unauthorized access and reduces the risk of ransomware gaining entry through compromised credentials.

How Long Does It Take to Recover from Ransomware?

The recovery time from a ransomware attack varies based on several factors:

Immediate Containment: Isolating infected systems from the network can take a few hours to a day, depending on the extent of the infection. Immediate containment is crucial to prevent further spread.

Restoration of Data: The time required to restore data depends on the availability and integrity of backups. Restoring from backups can range from hours to days, depending on the backup solution and the amount of data.

System Rebuilding: In cases where backups are unavailable or compromised, rebuilding systems from scratch may be necessary. This process can be time-consuming and may involve reinstallation of operating systems and applications.

Post-Incident Analysis: Conducting a thorough analysis to understand the attack vector, impact, and remediation steps can take additional time. This phase is critical for improving defenses and preventing future attacks.

How Lepide Can Help

Lepide’s Data Security Platform offers a comprehensive ransomware protection solution designed to provide real-time visibility and automated responses to possible threats. By focusing on reducing your attack surface, Lepide helps identify and mitigate risks like inactive user accounts, excessive permissions, and open shares.

It detects the early signs of ransomware attacks, such as unusual file activity or behavioral changes, and responds instantly with automated actions, such as shutting down compromised accounts. With detailed audit logs, Lepide ensures you have the insights needed to investigate and recover swiftly.

Conclusion

In the face of increasing ransomware threats, understanding and preparation are your strongest allies. Ransomware isn’t just about the loss of data; it’s about the disruption of trust and operations. By comprehensively understanding how ransomware operates and taking proactive steps to protect your systems, you can significantly mitigate risks. It’s about being vigilant, investing in the right security solutions, and knowing that with the proper precautions in place, you’re not just reacting to threats—you’re staying ahead of them.

If you want to know more about how Lepide’s Data Security Platform can help you protect against Ransomware, book a demo with one of our engineers today.