Ransomware

What Is Ransomware?

Ransomware, also known as ransom malware, is a type of malicious software that carries out denial-of-access attacks. What sets ransomware apart is its ability to lock victims' computers or systematically encrypt files on their hard drives until a ransom is paid. Victims of ransomware are required to pay a ransom to regain control of their computers or obtain decryption keys needed to decrypt the files. This type of malware is often distributed through Trojan horses, masquerading as legitimate files. It typically utilizes phishing emails or other forms of social engineering to trick victims into clicking on download links. Ransomware, like many other worm viruses, can also propagate across computers on the Internet by exploiting software vulnerabilities.

Preventing Ransomware Attacks

The most effective way to prevent ransomware attacks is to stop them from infiltrating organizations.

Host Protection

Firstly, it is advisable to centrally configure hosts using an organization-level IT infrastructure solution. Utilizing group policies of AD servers and the control center of enterprise-edition antivirus software can ensure the proper implementation of security measures without relying on employees to execute operations.

Secondly, it is crucial to educate employees on information security. Many ransomware attacks use emails or other social engineering tactics to entice employees into downloading malware or visiting malicious websites. Employees can avoid triggering these attacks by resisting the temptation. An effective strategy to prevent ransomware attacks is to promote information security, train employees to adopt good work habits, and help them recognize and thwart typical attack methods.

The following outlines the most critical host protection measures, many of which can be centrally implemented using IT infrastructure solutions. Small and micro enterprises without comprehensive IT systems can have their employees implement these measures after receiving appropriate training. The measures include, but are not limited to:

• Implementing account lock policies.

• Patching vulnerabilities exploited by ransomware.

• Enabling the system firewall to block or disable specific ports.

• Updating antivirus software to the latest version or deploying a professional antivirus tool.

• Ensuring login and authentication usernames and passwords meet complexity requirements.

• Avoid opening email attachments or clicking links from unknown sources.

• Preventing automatic macro execution and using caution when enabling macros.

• Downloading software only from approved sources.

• Regularly performing remote backups, ensures data can be quickly restored after an infection, as local data may remain encrypted even after paying a ransom.

• Displaying file name extensions in Windows folders to facilitate the detection of potentially malicious files.

Network Protection

The key to preventing ransomware attacks is to intercept them before they can enter the organization and cause significant damage. The best approach is to establish a multi-layered security protection system using firewalls, as attackers can easily bypass a single-layer defense. Strict security policies are the simplest and most effective protective measures. Only necessary services should be accessible to external systems, and high-risk ports should be blocked to minimize risk exposure (attack surface). Blocking known threats forces attackers to either create new ransomware or exploit new vulnerabilities, which increases their costs. Additionally, enabling file filtering can prevent high-risk files from entering networks, while URL filtering can block malicious websites, preventing users from inadvertently downloading malware. For networks requiring high security, deploying the FireHunter, HiSec Insight, and deception systems can provide comprehensive security monitoring and detection.

How to Deal with Ransomware?

Common suggestions for dealing with ransomware include, but are not limited to:

• Isolating infected devices. Disconnect network cables or modify network connection settings to isolate all devices infected with ransomware from the network. This prevents ransomware from spreading and helps control the impact. Then, assess the number of affected hosts and record the symptoms. Disable high-risk ports on other uninfected devices on the LANs, or specify which users or computers can access these ports.

• Remove ransomware. Restart the operating system and enter safe mode. Install antivirus software to scan all disks and remove the ransomware. Ransomware typically takes some time to search for and encrypt files. Remove the ransomware as soon as possible to limit its damage and prevent it from repeatedly locking the system or encrypting files.

• Decrypt. Do not immediately reinstall the operating system. If encrypted data is important, back it up and protect the environment to prevent decryption failures due to environmental damage. Visit the No More Ransom website, use Crypto Sheriff to identify the type of ransomware, and check if there is a decryption solution available to unlock and restore the files.

• Conduct a forensic investigation. Engage professional cybersecurity teams to gather evidence for analyzing and tracing the ransomware attack path. Review security logs in the operating system's Event Viewer, focusing on login failure events. Also, review security logs and session logs on network devices, especially for major vulnerability attacks like brute-force cracking and SMB. Identify the cause of the virus infection and address any security issues in the system to prevent future infections.

• Reinstall the operating system. If the ransomware cannot be removed and the encrypted data cannot be restored, back up the encrypted data (which may be restorable in the future), format the hard disk drive, delete all data (including infected data), and reinstall the operating system and application programs.