What Is Ransomware

Ransomware is malware that encrypts files on an infected computer and demands a ransom in exchange for the decryption key. Ransoms are typically demanded in hard-to-trace cryptocurrencies such as Bitcoin.

Modern ransomware goes beyond simple file encryption - "double extortion" has become the norm. In addition to encrypting files, attackers exfiltrate data before encryption and threaten to publish it on leak sites if the ransom is not paid. Some groups have escalated to "triple extortion," adding DDoS attacks or directly contacting the victim's customers and partners.

Major Infection Vectors

Phishing Emails: The most common infection vector. Victims are tricked into opening attachments (macro-enabled Office files, executables inside ZIP archives) disguised as invoices or delivery notifications. Recent variants also abuse OneNote files and ISO images.
VPN Appliance Vulnerabilities: Exploiting unpatched VPN devices to infiltrate corporate networks. Vulnerabilities in Fortinet and Pulse Secure products have been repeatedly targeted. Many organizations delay patching, leaving them exposed.
RDP (Remote Desktop) Brute Force: Attacking internet-exposed RDP ports with brute-force or credential-stuffing attacks. Weak passwords and lack of multi-factor authentication make this vector highly effective.
Supply Chain Compromise: Injecting ransomware through legitimate software updates. The Kaseya incident (2021) distributed ransomware to over 1,500 organizations through a managed service provider's update mechanism.

Effective Prevention Strategies

Preventing ransomware damage requires a multi-layered approach.

Practice the 3-2-1 Backup Rule: Keep 3 copies of data on 2 different media types with 1 copy offsite. Since ransomware also encrypts network-accessible backups, offline backups (air-gapped) are essential.
Prompt Patch Management: Apply security patches for OS, VPN appliances, and applications as quickly as possible. Prioritize patches for vulnerabilities with known exploits.
Network Segmentation: Divide the network into segments to contain the spread if one segment is compromised. Isolate critical systems and backup servers in separate segments.
Endpoint Detection and Response (EDR): Deploy EDR solutions that detect suspicious behavior (mass file encryption, shadow copy deletion) and automatically isolate affected endpoints.
Email Security: Implement email filtering to block malicious attachments and URLs. Sandbox analysis of attachments adds another layer of protection.

Incident Response Steps

If infected with ransomware, stay calm and follow these steps.

Disconnect from the Network Immediately: Unplug the LAN cable and disable Wi-Fi on the infected device. Preventing lateral spread is the top priority.
Do Not Pay the Ransom: There is no guarantee that paying will result in receiving the decryption key. Payment funds criminal operations and marks your organization as a "paying target" for future attacks.
Check for Decryption Tools: The No More Ransom project (nomoreransom.org) provides free decryption tools for some ransomware variants. Identify the ransomware strain and check for available tools.
Restore from Backups: After confirming the infection is contained, restore systems from clean backups. Verify that backups are not also encrypted before restoring.
Report and Investigate: Report to law enforcement and your national cybersecurity agency. Conduct a forensic investigation to identify the infection vector and prevent recurrence.

To learn more about this topic, see Ransomware Protection Guide: Defending Against Extortion Attacks.

Common Misconceptions

Ransomware only targets large enterprises: Small and medium businesses and individuals are frequently targeted. SMBs with limited security measures are actually preferred as "easy targets." Numerous incidents involving hospitals, municipalities, and small manufacturers have been reported.
Paying the ransom guarantees data recovery: Cases have been reported where the decryption key was not provided after payment, decryption failed, or only some files were recovered. Organizations that pay once tend to be re-targeted as "proven payers."

Ransomware