PULSE NAME
Kyber Ransomware Double Trouble: Windows and ESXi Attacks Explained
WHITE Kyber AlienVault 2026-04-22 Modified: 2026-04-22
5
IOCs
LOW VOLUME
Kyber ransomware represents a significant threat through dual-platform deployment capabilities targeting VMware ESXi virtualization infrastructure and Windows file systems. During a March 2026 incident response engagement, two Kyber payloads were recovered from the same environment. The ESXi variant, written in C++, specifically targets VMware environments with datastore encryption, VM termination, and management interface defacement capabilities. The Windows variant, written in Rust, includes experimental Hyper-V targeting features. Both samples share campaign identifiers and Tor-based infrastructure, confirming coordinated cross-platform operations. Despite advertising post-quantum Kyber1024 encryption, the ESXi variant actually uses ChaCha8 with RSA-4096 key wrapping, while the Windows variant implements the claimed AES-256-CTR with Kyber1024 hybrid scheme. The ransomware includes anti-recovery measures, service termination, and effective encryption strategies designed to cause complete operational disr...
Indicators of Compromise (5)
All FileHash-MD5 FileHash-SHA1 FileHash-SHA256
TYPEINDICATORDESCRIPTIONCREATED
FileHash-MD5 18498b1ff111ee9d9a037c280f75b720 2026-04-22
FileHash-SHA1 0e9a47782e39741a2c161bf639252d33ad3a428a 2026-04-22
FileHash-SHA256 45bff0df2c408b3f589aed984cc331b617021ecbea57171dac719b5f545f5e8d 2026-04-22
FileHash-SHA256 4ed176edb75ae2114cda8cfb3f83ac2ecdc4476fa1ef30ad8c81a54c0a223a29 2026-04-22
FileHash-SHA256 6ccacb7567b6c0bd2ca8e68ff59d5ef21e8f47fc1af70d4d88a421f1fc5280fc 2026-04-22