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HelloKitty Ransomware

HelloKitty is a newly seen ransomware that uses an incredibly noisy infection routine.

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

HelloKitty is a newly seen ransomware that uses an incredibly noisy infection routine.


Affected platforms

The following platforms are known to be affected:

Threat details

Introduction

First observed in November 2020, HelloKitty gets its name from the mutex that is used when the ransomware is executed. It has been involved in several high profile attacks since it was first seen last year. There is some speculation that HelloKitty and DeathRansom are related, although this has not been confirmed.


Delivery

At the time of publication, it is unclear how HelloKitty is delivered. However, there are unconfirmed reports that it may be delivered via phishing or as a secondary payload.


Activities

After being deployed, HelloKitty will terminate certain security, database, and recovery services and processes to make encryption easier. It will then deploy its hybrid encryption implementation. After appending .crypted to the affected files, it creates a bespoke ransom note, directing payment to a Tor-based portal.


Remediation advice

If a device on your network becomes infected with ransomware it will begin encrypting files, which may also include remote files on network locations. The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup. To limit the impact of a ransomware infection, NHS Digital advises that:

  • Critical data is frequently saved in multiple backup locations.
  • At least one backup is kept offline at any time (separated from live systems).
  • Backups and incident recovery plans are tested to ensure that data can be restored when needed.
  • User account permissions for modifying data are regularly reviewed and restricted to the minimum necessary.
  • Infected systems are disconnected from the network and powered down as soon as practicable.
  • Any user account credentials that may have been compromised should be reset on a clean device
  • Where infected systems cannot be quarantined with confidence, then an affected organisation should disconnect from national networks to limit propagation.

Additionally, to prevent and detect an infection, NHS Digital advises that:

  • Secure configurations are applied to all devices.
  • Security updates are applied at the earliest opportunity.
  • Tamper protection settings in security products are enabled where available.
  • Obsolete platforms are segregated from the rest of the network.
  • IT usage policies are reinforced by regular training to ensure all users know not to open unsolicited links or attachments.
  • Multi-factor authentication (MFA) and lockout policies are used where practicable, especially for administrative accounts.
  • Administrative accounts are only used for necessary purposes.
  • Remote administration services use strongly encrypted protocols and only accept connections from authorised users or locations.
  • Systems are continuously monitored, and unusual activity is investigated, so that a compromise of the network can be detected as early as possible.

Please note that NCSC maintains guidance for securely configuring a wide range of end user device (EUD) platforms. For further details refer to their end user device security guidance pages.


Indicators of compromise

Host indicators

SHA1 hashes

  • fadd8d7c13a18c251ded1f645ffea18a37f1c2de

SHA-256 hashes

  • 501487b025f25ddf1ca32deb57a2b4db43ccf6635c1edc74b9cff54ce0e5bcfe

Last edited: 11 March 2021 2:57 pm