Hello Kitty Ransomware: In-Depth Analysis, Detection, and Mitigation

Summary of Hello Kitty Ransomware

The Hello Kitty ransomware family emerged in late 2020, operating out of Ukraine.  The ransomware family gained attention via the attack against CD Projekt Red.  The name is derived from the “HelloKittyMutex” created upon execution of the threat.  Hello Kitty is known for being nimble and rapidly adopting new TTPs.  Later variants of Hello Kitty used a Golang-based packer to improve detection evasion.  In early 2021, a Linux variation of Hello Kitty was observed in the wild.

Hello Kitty Ransomware

What Does Hello Kitty Ransomware Target?

Hello Kitty ransomware targets small-to-medium businesses (SMB) as well as technology, manufacturing and financial services organizations.

How Does Hello Kitty Ransomware Spread?

Hello Kitty is deployed in multiple ways: via Cobalt Strike or a similar framework, and through email phishing.  Hello Kitty ransomware has also been deployed as a later-stage payload in previously-infected environments (example: Qakbot, IcedID)

Hello Kitty Ransomware Technical Details

Once launched, Hello Kitty will attempt to disable and terminate a number of processes and services so as to reduce interference with the encryption process. This includes processes and services associated with IIS, MSSQL, Quickbooks, Sharepoint, and more. These actions are carried out via taskkill.exe and net.exe.

If Hello Kitty is unable to stop any specific processes or services, it will engage the Windows Restart Manager API to further assist in termination.

Hello Kitty will also utilize WMI to gather system details and help identify running processes and any potentially problematic processes. This is done both by name and by PID.

Encryption is initiated and completed very quickly once applicable services and processes have been terminated. Specific encryption recipes and routines can vary across variants of HelloKitty. Generally speaking, they tend to use a combination of AES-256 and RSA-2048 or even NTRU+AES-128.Ransom notes are typically customized to directly reference the victim and victim’s environment. Victims are instructed to visit a TOR-based payment and support portal.

How to Detect Hello Kitty Ransomware

  • The SentinelOne Singularity XDR Platform can identify and stop any malicious activities and items related to Hello Kitty Ransomware

In case you do not have SentinelOne deployed, detecting ransomware requires a combination of technical and operational measures designed to identify and flag suspicious activity on the network. This allows the organization to take appropriate action, and to prevent or mitigate the impact of the ransomware attack.

To mitigate the risk of this Ransomware without SentinelOne deployed, it is important to take a multi-layered approach, which includes the following steps:

  1. Use anti-malware software or other security tools capable of detecting and blocking known ransomware variants. These tools may use signatures, heuristics, or machine learning algorithms, to identify and block suspicious files or activities.
  2. Monitor network traffic and look for indicators of compromise, such as unusual network traffic patterns or communication with known command-and-control servers.
  3. Conduct regular security audits and assessments to identify network and system vulnerabilities and ensure that all security controls are in place and functioning properly.
  4. Educate and train employees on cybersecurity best practices, including identifying and reporting suspicious emails or other threats.
  5. Implement a robust backup and recovery plan to ensure that the organization has a copy of its data and can restore it in case of an attack.

How to Mitigate Hello Kitty Ransomware

  • The SentinelOne Singularity XDR Platform can return systems to their original state (which is free from re-infection) using either the Repair or Rollback feature.

In case you do not have SentinelOne deployed, there are several steps that organizations can take to mitigate the risk of ransomware attacks:

  1. Educate employees: Employees should be educated on the risks of ransomware, and on how to identify and avoid phishing emails, malicious attachments, and other threats. They should be encouraged to report suspicious emails or attachments, and to avoid opening them, or clicking on links or buttons in them.
  2. Implement strong passwords: Organizations should implement strong, unique passwords for all user accounts, and should regularly update and rotate these passwords. Passwords should be at least 8 characters long, and should include a combination of uppercase and lowercase letters, numbers, and special characters.
  3. Enable multi-factor authentication: Organizations should enable multi-factor authentication (MFA) for all user accounts, to provide an additional layer of security. This can be done through the use of mobile apps, such as Google Authenticator or Microsoft Authenticator, or through the use of physical tokens or smart cards.
  4. Update and patch systems: Organizations should regularly update and patch their systems, to fix any known vulnerabilities, and to prevent attackers from exploiting them. This includes updating the operating system, applications, and firmware on all devices, as well as disabling any unnecessary or unused services or protocols.

Implement backup and disaster recovery: Organizations should implement regular backup and disaster recovery (BDR) processes, to ensure that they can recover from ransomware attacks, or other disasters. This includes creating regular backups of all data and systems, and storing these backups in a secure, offsite location. The backups should be tested regularly, to ensure that they are working, and that they can be restored quickly and easily.

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