Malware
HelloKitty
aka KittyCrypt
Unit42 states that HelloKitty is a ransomware family that first surfaced at the end of 2020, primarily targeting Windows systems.
HelloKitty, also known as KittyCrypt, is a Windows malware family.
Background
Per Unit42, HelloKitty is a ransomware family that emerged in late 2020 and chiefly goes after Windows systems. Its name comes from the mutex it creates, HelloKittyMutex. The samples appear to change rapidly and often, with various builds appending the .crypted or .kitty extension to encrypted files. Certain newer variants employ a Golang packer that keeps the final ransomware payload memory-resident, likely to slip past security products.
Source: Malpedia (Fraunhofer FKIE).