Recovery of files affected by Ryuk Ransomware

Preventing a Ryuk ransomware attack requires a comprehensive cybersecurity framework, but that’s not all, let’s list some important points that you need to pay attention to.

• Organisation – Having documentation of the IT park helps a lot in the prevention process, in addition to the inventory of networks and computers. Develop rules so that new employees have clear company policy on the installation and use of programmes on computers.
• Strong Passwords – Passwords should be strong, containing more than 8 digits, including special ones. And do not use a single password for multiple credentials.
• Security Solutions – Have a good antivirus installed, keep all programmes up to date, especially the operating system. Besides the antivirus solution, you need a Firewall and endpoints. They will make sure that the system stays protected.
• Beware of suspicious emails – One of the most used means for invasion used by hacker groups are spam email campaigns, so it is vital to create a security and awareness policy for employees not to download attached files sent by unknown emails.
• Efficient backup policies – Backups are essential for any eventual incident, but even with this essential role many companies neglect it or create a backup schedule that is not effective. We have already assisted several clients that not only the data was encrypted, but also the backups. It is not recommended to keep online backups only. The best backup structure is 3x2x1, which is 3 backups, 2 online and 1 offline, in addition to creating a consistent routine of updating the backups.
• Beware of unofficial programmes – There are numerous paid programmes that are made available for free on the Internet, such as Windows, Office and many others. They may appear to be free at first, but in the future can be used as a gateway for future hacker attacks. Even if official programmes demand financial resources, they are a good investment and are also secure.

The most common means of access used by Ryuk hackers to break into environments is through exploiting vulnerabilities in software, hardware, or human behaviour. This can include:

1. Phishing attacks: Hackers use fraudulent emails, social media messages, or phone calls to trick individuals into revealing their login credentials or other sensitive information.
2. Password attacks: Hackers use various techniques, such as brute force or dictionary attacks, to guess or crack passwords.
3. Malware: Hackers use malicious software, such as viruses, worms, or Trojans, to infect computers or other devices and gain access to sensitive data.
4. Software vulnerabilities: Hackers use known vulnerabilities in software, such as operating systems, web servers, or applications, to gain unauthorised access to a system.
5. Misconfigured or unpatched systems: Hackers exploit weaknesses in system configurations or outdated software that has not been patched or updated to gain access.
6. Social engineering: Hackers use social engineering techniques, such as pretexting or baiting, to manipulate individuals into divulging sensitive information or granting access to secure systems.

To reduce the risk of a successful attack, it’s important to implement security best practises, such as strong passwords, two-factor authentication, regular software updates and patches, employee security awareness training, and the use of security tools like firewalls, intrusion detection systems, and antivirus software.

High consumption of processing, memory and disk access are suspicious behaviours that need to be investigated thoroughly in order to assess whether an attack is underway.

The Ryuk ransomware uses the machine’s own resources to perform exfiltration. In order to encrypt the machine this demands the use of its own resources.

It is also possible to detect the attack by the changes made to the file extensions, this type of detection is a bit more complex because the encryption process will have already been started.

If your machine is affected by Ryuk ransomware, your data will be inaccessible until the encryption is removed. Unfortunately, removing the encryption typically requires formatting the affected machine, which will result in the loss of all stored data.

However, some ransomware attackers also use the double extortion tactic, which involves copying and extracting all files from the affected machine and then encrypting the original data. In such cases, the attackers may post the stolen files on their website or Dark Web forums while keeping the original data encrypted on the affected machine. In such scenarios, formatting the device will not recover the original data, and the only way to retrieve the stolen files may be to pay the ransom or seek professional help.