Guide to the Linux IceFire Ransomware Variant

IceFire Ransomware, which already utilizes exploits in cybersecurity to attack Linux systems, has recently developed a new strain. This threat takes advantage of an IBM Aspera Faspex file-sharing vulnerability (CVE-2022-47986) that had previously only targeted Windows systems and media and entertainment companies. Since Linux systems tend to be quite powerful in mitigating risks, IceFire Ransomware is all the more concerning, as it can breach robust cybersecurity systems and cause substantial harm.

The ransomware operators' tactics are consistent with those of the "Big-Game Hunting (BGH)" ransomware families, as the variant focuses on attacking large enterprises, leveraging double extortion, utilizing evasion techniques like deleting log files, and implementing numerous persistence mechanisms. Double extortions are detrimental since these attacks in network security typically demand twice as much for the ransom payment. 

As network security issues rise, you must stay up-to-date on the latest security news. Knowing the best security practices can help you mitigate risks before they damage your server. This article will review ransomware, dive into IceFire Ransomware, and show you how to protect your server.

What Is Ransomware?

Ransomware cybercriminals focus on breaching a company’s system, decrypting sensitive files and valuable data, and forcing victims to pay a ransom, or a large sum of money, before returning company work to employees. This type of malware is more damaging to a business than typical malware and phishing email attacks since money is involved.

What Does a Ransomware Attack Look Like?

During a ransomware attack, users might receive a phishing email that appears to be from a trustworthy sender due to the use of social engineering tactics. Users will open the message and download attachments or links that lead to legitimate-looking documents and websites. Then, cybercriminals can install ransomware they please onto a server, infecting a system and taking away primary access to data companies need for daily operations.

What is IceFire Ransomware and its Characteristics?

IceFire Ransomware on Linux systems comes across as 2.18 MBs, 64-bit Executables, and Linkable Binary Files (ELF) with open-source GNU Compiler Collection (GCC) for AMD64 system processor architecture. Cybercriminals deployed the services against CentOS hosts so they could run successfully on Intel-based Ubuntu and Debian distributions.

Impacted systems download the IceFire payloads, execute them to encrypt files, and rename them with the ".ifire" extension. Then the payload stealthily deletes itself to avoid detection. IceFire Linux payload scripts exclude encryption for specific system-critical files and paths like the following: .cfg, .o, .sh, .img, .txt, .xml, .jar, .pid, .ini, .pyc, .a, .so, .run, .env, .cache, .xmlb, p, /boot, /dev, /etc, /lib, /proc, /srv, /sys, /usr, /var, /run.

This intentional deletion prevents encryption so companies can still operate their server. The variant exploits cybersecurity vulnerabilities by implementing itself into the system rather than relying on phishing emails and third-party frameworks. As a result, network security threats may go undetected for an extended period while devising a plan of attack. Once the business faces a breach, there is very little they can do to stop it since the cybercriminals have done extensive research when sitting inside the company's server for so long.

The Linux IceFire ransomware payload uses an RSA encryption algorithm with an RSA public key hard-coded into the binary. The payload drops a ransom note from an embedded resource and writes it to each directory targeted for file encryption. The ransom note includes a predefined username and password that you must use to access the ransom payment website hosted on a Tor hidden service to ensure anonymity.

How Could IceFire Break Into Secure Linux Systems?

Linux security expert and LinuxSecurity.com Founder Dave Wreski remarks, “Linux presents more challenges for ransomware operators than Windows, especially on a large scale. Many Linux systems are servers less susceptible to common infection methods like phishing or drive-by downloads. Thus, attackers have resorted to exploiting application vulnerabilities, as we have recently seen with the IceFire ransomware group.”

How Can I Secure My Linux Systems Against IceFire Ransomware?

Cybercriminals target Linux operating systems more frequently since their highly secure servers outperform Windows and macOS in data and network security. More online customers rely on Linux to power a company's high-value devices as the necessity for email protection skyrockets. Malware, rootkits, and more malicious network security threats put Linux users at risk even more as the system popularizes. Unfortunately, we know only one threat management platform that can combat and stop evasive ransomware attacks in network security: Vali Cyber's ZeroLock.

What is ZeroLock? How Can It Protect Against IceFire?

ZeroLock rapidly and reliably reacts to attacks in network security by deploying email security solutions that effectively combat malware, rootkits, and ransomware. This service injects code into all aspects of a system so it can monitor the controls organizations use frequently. ZeroLock can suspend, delete, or cache any files, links, or downloads that it considers suspicious. Cybersecurity hardening with ZeroLock keeps cloud security breaches far away from your business and ensures email protection throughout your server.

What Other Email Security Options Do I Have to Combat Threats?

If you are searching for solutions to add to your security tactics on top of Vali Cyber’s ZeroLock, consider implementing these best email security practices that can improve security posture in your Linux system:

• Stay up-to-date on the latest cybersecurity vulnerabilities impacting your systems. Register as a LinuxSecurity user, subscribe to our Advisory Watch newsletter, and customize your advisories based on distros to know the latest security news that could cause network security issues for your business. Follow @LS_Advisories on X for real-time updates.
• Avoid a Single Point of Failure (SPOF) attack by backing up critical files and diversifying your storage media so cybercriminals cannot utilize repetition in a breach. This solution will not stop attacks, but it can mitigate damage.
• Integrate the principle of least privilege for your users so accounts only provide the access an employee needs and nothing more, reducing the likeliness of an internal breach.
• Monitor network activity and system logs closely to stop any attack or risk as quickly as possible.
• Identify anomalous behavior when keeping tabs on event activity. Regularly checking prevents harm from reaching your company.
• Use a combination of IP filtering, an Intrusion Detection System (IDS), and an Intrusion Prevention System (IPS). These three options can quickly improve security posture and combat more network security threats.
• Use Linux security extensions that control and restrict access to data or network resources. Such applications will prevent cybersecurity vulnerabilities from being abused during a possible attack.
• Implement robust network segmentation and data compartmentalization to minimize the impact of a potential ransomware attack.
• Utilize cloud security audits on systems regularly. Test them and utilize security patching as needed to prevent any risk that could severely harm the productivity of your business.

Our Final Thoughts on Securing Linux Systems Against Ransomware

Understanding the data and network security issues you may face during a ransomware attack is vital in guaranteeing your company knows how to protect itself from such threats in the first place. IceFire can encrypt files and delete itself from servers to go undetected when hacking into a system and inflicting damage. Although IceFire Ransomware is not the most significant risk out there, it can be detrimental to a business, especially considering it can get through Linux security systems, which are relatively defensive in their approach to email security. Fortunately, you can utilize various solutions to prevent an IceFire attack from reaching your organization.

Wreski concludes, "Linux ransomware is a serious and increasingly prevalent threat, but luckily, attacks can be prevented with sound administration, the implementation of the right technology,  and the other security best practices shared in this article." Continue learning how to strengthen your server's email protection by checking out our blog and articles about other types of ransomware and phishing attacks reaching Linux systems.