VNC (Virtual Network Computing) to the Internet
This rule detects network events that may indicate the use of VNC traffic to the Internet. VNC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It…
Description
This rule detects network events that may indicate the use of VNC traffic to the Internet. VNC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector.
Detection logic
Its licence does not clear it for publishing here
Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.
Detection requirements
Known benign triggers
- VNC connections may be made directly to Linux cloud server instances but such connections are usually made only by engineers. VNC is less common than SSH or RDP but may be required by some work flows such as remote access and support for specialized software products or servers. Such work-flows are usually known and not unexpected. Usage that is unfamiliar to server or network owners can be unexpected and suspicious.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml | 20 |
From the source
- At source
- Open at source
- Upstream identifier
- 3ad49c61-7adc-42c1-b788-732eda2f5abf
- Tagged by the source as
- Data Source: FortinetData Source: Network Packet CaptureData Source: PAN-OSData Source: pfSenseDomain: EndpointDomain: NetworkNoise: MediumPerformance: NormalResources: Investigation GuideRule Type: Custom Query (KQL)Tactic: Command and ControlTactic: Lateral MovementUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 4