Analytics Story: VoidLink Cloud-Native Linux Malware

Date: 2026-01-20 ID: 8f3e9a2c-4d7b-11ef-9c8a-acde48001122 Author: Michael Haag, Splunk Product: Splunk Enterprise Security

Description

Detect and investigate VoidLink, an advanced cloud-native Linux malware framework discovered by Check Point Research in December 2025. VoidLink is a sophisticated, modular C2 framework written in Zig that targets cloud and containerized infrastructure with 30+ plugins, multiple rootkit capabilities (LD_PRELOAD, LKM, eBPF), and adaptive evasion mechanisms. The framework demonstrates commercial-grade development with Chinese-affiliated origins and is designed for long-term persistence, credential theft, and data exfiltration in AWS, GCP, Azure, Alibaba, and Tencent cloud environments. Monitor for cloud metadata service abuse, container escape attempts, systemd/cron persistence, LD_PRELOAD hijacking, kernel module loading, SSH lateral movement, and Linux-specific defense evasion techniques including log tampering and rootkit deployment. VoidLink's plugin-based architecture and cloud-first tradecraft make it particularly dangerous in modern containerized and Kubernetes environments.

Why it matters

VoidLink represents a significant evolution in Linux malware targeting cloud-native infrastructure. Discovered by Check Point Research in December 2025, this framework showcases advanced capabilities specifically designed for cloud and container environments. The malware can detect which cloud provider it's running on (AWS, GCP, Azure, Alibaba, Tencent), identify if it's in a Docker container or Kubernetes pod, and adjust its behavior accordingly. VoidLink's modular plugin system, inspired by Cobalt Strike's Beacon Object Files (BOF), allows operators to dynamically load over 30 specialized modules at runtime for reconnaissance, credential access, persistence, privilege escalation, and data exfiltration. The framework employs multiple rootkit mechanisms including user-mode LD_PRELOAD hijacking, kernel-level LKM rootkits, and modern eBPF-based hiding techniques. Its command and control infrastructure supports HTTP/HTTPS, DNS tunneling, ICMP tunneling, and P2P mesh communication between compromised hosts. VoidLink's operational security features include runtime code encryption, self-deletion upon tampering detection, and adaptive evasion that modifies behavior based on detected security products. The framework's cloud-first design includes dedicated modules for cloud metadata harvesting, container secret extraction, Kubernetes privilege escalation, and automated credential theft from cloud environments. Detection requires comprehensive visibility across Linux endpoints, container runtimes, Kubernetes audit logs, and cloud provider activity logs. Key detection opportunities include monitoring for cloud metadata service access (169.254.169.254), systemd service file creation, cron job manipulation, LD_PRELOAD environment variable usage, kernel module loading, SSH key modifications, and suspicious process execution patterns within containers. Organizations running containerized workloads in cloud environments should prioritize detection of container escape attempts, Kubernetes RBAC abuse, and cloud credential theft as VoidLink specifically targets these attack vectors for initial access and privilege escalation.

Detections

Name ▲▼	Technique ▲▼	Type ▲▼
Cisco Isovalent - Access To Cloud Metadata Service	Cloud Instance Metadata API	Anomaly
Cisco Isovalent - Kprobe Spike	Exploitation for Privilege Escalation	Hunting
Cisco Isovalent - Potential Escape to Host	Escape to Host	Anomaly
Linux Adding Crontab Using List Parameter	Cron	Hunting
Linux Auditd Preload Hijack Via Preload File	Dynamic Linker Hijacking	TTP
Linux Install Kernel Module Using Modprobe Utility	Kernel Modules and Extensions	Anomaly
Linux Medusa Rootkit	Rootkit, Credentials	TTP
Linux Preload Hijack Library Calls	Dynamic Linker Hijacking	TTP
Linux Service File Created In Systemd Directory	Systemd Timers	Anomaly
Linux SSH Authorized Keys Modification	SSH Authorized Keys	Anomaly
Linux SSH Remote Services Script Execute	SSH	TTP
Linux Sudo OR Su Execution	Sudo and Sudo Caching	Hunting
Linux System Network Discovery	System Network Configuration Discovery	Anomaly
Suspicious Linux Discovery Commands	Unix Shell	TTP
Suspicious wevtutil Usage	Clear Windows Event Logs	TTP
Detect DNS Data Exfiltration using pretrained model in DSDL	Exfiltration Over Unencrypted Non-C2 Protocol	Anomaly
Detect suspicious DNS TXT records using pretrained model in DSDL	Domain Generation Algorithms	Anomaly

Data Sources

Name ▲▼	Platform ▲▼	Sourcetype ▲▼	Source ▲▼
Cisco Isovalent Process Connect	Other	`cisco:isovalent:processConnect`	`not_applicable`
Cisco Isovalent Process Exec	Other	`cisco:isovalent:processExec`	`not_applicable`
Cisco Isovalent Process Kprobe	Other	`cisco:isovalent`	`not_applicable`
CrowdStrike ProcessRollup2	Other	`crowdstrike:events:sensor`	`crowdstrike`
Linux Auditd Cwd	Linux	`auditd`	`auditd`
Linux Auditd Path	Linux	`auditd`	`auditd`
Sysmon EventID 1	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon for Linux EventID 1	Linux	`sysmon:linux`	`Syslog:Linux-Sysmon/Operational`
Sysmon for Linux EventID 11	Linux	`sysmon:linux`	`Syslog:Linux-Sysmon/Operational`
Windows Event Log Security 4688	Windows	`XmlWinEventLog`	`XmlWinEventLog:Security`

References

Source: GitHub | Version: 1