Sigma Rule Library

Cloudflared Tunnel Execution

Detects execution of the "cloudflared" tool to connect back to a tunnel. This was seen used by threat actors to maintain persistence and remote access to compromised networks.

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Detection logic

selection

CommandLine|contains|all:
  - " tunnel "
  - " run "
CommandLine|contains:
  - "-config "
  - "-credentials-contents "
  - "-credentials-file "
  - "-token "

Condition

selection

Raw YAML

title: Cloudflared Tunnel Execution
id: 9a019ffc-3580-4c9d-8d87-079f7e8d3fd4
status: test
description: Detects execution of the "cloudflared" tool to connect back to a tunnel. This was seen used by threat actors to maintain persistence and remote access to compromised networks.
references:
    - https://blog.reconinfosec.com/emergence-of-akira-ransomware-group
    - https://github.com/cloudflare/cloudflared
    - https://developers.cloudflare.com/cloudflare-one/connections/connect-apps
author: Janantha Marasinghe, Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-17
modified: 2023-12-20
tags:
    - attack.command-and-control
    - attack.t1102
    - attack.t1090
    - attack.t1572
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - ' tunnel '
            - ' run '
        CommandLine|contains:
            - '-config '
            - '-credentials-contents '
            - '-credentials-file '
            - '-token '
    condition: selection
falsepositives:
    - Legitimate usage of Cloudflared tunnel.
level: medium

False positives

  • Legitimate usage of Cloudflared tunnel.

References

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