The source code for the well-known Hello Kitty ransomware was posted on to a Russian-speaking hacking forum recently, the first time this code has been seen publicly since the group started in 2020.

In the post, the threat actor suggests that this version of the code is no longer required, and a more effective version is being developed.

Hello Kitty are a ransomware group, known for targeting corporate networks within technology, manufacturing and finance industries and utilises other malware including cobalt strike.

Hello Kitty has also been observed in already infected environments, being deployed as another payload stage after Qakbot or IcedID have been used.

The group engages in double extortion techniques, an increasingly common tactic used by threat actors, whereby victims are threatened with data leaks if they refuse to pay ransoms.

Hello Kitty has been associated with some large-scale attacks, including CD Project Red in 2021, a gaming studio in Poland, where they breached the internal network and encrypted files and systems.

Alongside this, Hello Kitty stole the source code of games, including an unreleased version of ‘Witcher 3’.

Recently, Hello Kitty have been linked to large scale leveraging of a VMware ESXi vulnerability, with the group utilising a Linux variant to target the virtual machine platform.

The threat actor is known by several aliases, including DeathRansom and Fivehands, and is thought to use the moniker “Gookee”.

Gookee has been observed previously attempting to sell access to companies, including Sony Network Japan and linked to a ransomware-as-a-service called “Gookee Ransomware”, selling malware source code on underground forums.

Researchers believe that Gookee is the developer of Hello Kitty ransomware, and is using the guise of another username, ‘kapuchin0’, to sell the code and replace it with one “much more interesting than Lockbit”.

While the release of malware source code is very useful for researchers and professionals to provide protection against this and future versions, it does mean that the code is publicly available for bad actors to take and develop future variants.

Reporting

Report all Fraud and Cybercrime to Action Fraud by calling 0300 123 2040 or online. Forward suspicious emails to report@phishing.gov.uk. Report SMS scams by forwarding the original message to 7726 (spells SPAM on the keypad).