Detection rules › Sigma
Cloudflared Tunnels Related DNS Requests
Detects DNS requests to Cloudflared tunnels domains. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
Known false positives
- Legitimate use of cloudflare tunnels will also trigger this.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 22: DNSEvent (DNS query) |
Rule body
title: Cloudflared Tunnels Related DNS Requests
id: a1d9eec5-33b2-4177-8d24-27fe754d0812
related:
- id: 7cd1dcdc-6edf-4896-86dc-d1f19ad64903
type: similar
status: test
description: |
Detects DNS requests to Cloudflared tunnels domains.
Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
references:
- https://www.guidepointsecurity.com/blog/tunnel-vision-cloudflared-abused-in-the-wild/
- Internal Research
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-12-20
tags:
- attack.command-and-control
- attack.t1071.001
- attack.t1572
logsource:
category: dns_query
product: windows
detection:
selection:
QueryName|endswith:
- '.v2.argotunnel.com'
- 'protocol-v2.argotunnel.com'
- 'trycloudflare.com'
- 'update.argotunnel.com'
condition: selection
falsepositives:
- Legitimate use of cloudflare tunnels will also trigger this.
level: medium
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
QueryName|endswith:
- '.v2.argotunnel.com'
- 'protocol-v2.argotunnel.com'
- 'trycloudflare.com'
- 'update.argotunnel.com'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
QueryName | ends_with |
| field:"QueryName" kind:ends_with |