Potential SIP REGISTER Brute Force
Identifies repeated SIP REGISTER authentication rejection responses for one or more extensions from a client to a VoIP server within five minutes. The rule distinguishes repeated failures from the single 401 or 407…
Description
Identifies repeated SIP REGISTER authentication rejection responses for one or more extensions from a client to a VoIP server within five minutes. The rule distinguishes repeated failures from the single 401 or 407 challenge expected in a normal digest-authentication flow. Attackers brute-force extension credentials to register rogue endpoints for toll fraud, call interception, or registration hijacking.
Detection logic
Its licence does not clear it for publishing here
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Detection requirements
- Platform
- ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
Known benign triggers
- Misconfigured phones, expired credentials, or provisioning errors can generate repeated REGISTER failures from a single device. Validate the client, affected extensions, and registration state before escalating.
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 |
|---|---|
| attack.mitre.org/techniques/T1110/ | 8from 2 sources |
From the source
- At source
- Open at source
- Upstream identifier
- 1ca59146-7386-4033-a010-1c32717e9321
- Tagged by the source as
- Data Source: Network Packet CaptureDomain: NetworkNoise: UnknownPerformance: FastProfile: RecommendedResources: Investigation GuideRule Type: ES|QLTactic: Credential AccessThreat: Brute ForceUse Case: Network Security MonitoringUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3