{"id":"7cd1dcdc-6edf-4896-86dc-d1f19ad64903","title":"Network Connection Initiated To Cloudflared Tunnels Domains","description":"Detects network connections to Cloudflared tunnels domains initiated by a process on the system.\nAttackers can abuse that feature to establish a reverse shell or persistence on a machine.\n","author":"Kamran Saifullah, Nasreddine Bencherchali (Nextron Systems)","status":"test","level":"medium","date":"2024-05-27","modified":"","tags":["attack.exfiltration","attack.command-and-control","attack.t1567","attack.t1572"],"technique_ids":["T1567","T1572"],"logsource":{"category":"network_connection","product":"windows"},"falsepositives":["Legitimate use of cloudflare tunnels will also trigger this."],"references":["https://defr0ggy.github.io/research/Abusing-Cloudflared-A-Proxy-Service-To-Host-Share-Applications/","https://www.guidepointsecurity.com/blog/tunnel-vision-cloudflared-abused-in-the-wild/","Internal Research"],"source_path":"rules/windows/network_connection/net_connection_win_domain_cloudflared_communication.yml","source_sha256":"8b5384579749a6c44d379535e6756a9726978ac84ee331856fb24ae0b3fced8f","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/network_connection/net_connection_win_domain_cloudflared_communication.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Network Connection Initiated To Cloudflared Tunnels Domains\nid: 7cd1dcdc-6edf-4896-86dc-d1f19ad64903\nrelated:\n    - id: a1d9eec5-33b2-4177-8d24-27fe754d0812\n      type: derived\nstatus: test\ndescription: |\n    Detects network connections to Cloudflared tunnels domains initiated by a process on the system.\n    Attackers can abuse that feature to establish a reverse shell or persistence on a machine.\nreferences:\n    - https://defr0ggy.github.io/research/Abusing-Cloudflared-A-Proxy-Service-To-Host-Share-Applications/\n    - https://www.guidepointsecurity.com/blog/tunnel-vision-cloudflared-abused-in-the-wild/\n    - Internal Research\nauthor: Kamran Saifullah, Nasreddine Bencherchali (Nextron Systems)\ndate: 2024-05-27\ntags:\n    - attack.exfiltration\n    - attack.command-and-control\n    - attack.t1567\n    - attack.t1572\nlogsource:\n    category: network_connection\n    product: windows\ndetection:\n    selection:\n        Initiated: 'true'\n        DestinationHostname|endswith:\n            - '.v2.argotunnel.com'\n            - 'protocol-v2.argotunnel.com'\n            - 'trycloudflare.com'\n            - 'update.argotunnel.com'\n    condition: selection\nfalsepositives:\n    - Legitimate use of cloudflare tunnels will also trigger this.\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1567","id":"T1567","name":"Exfiltration Over Web Service","page":"techniques/enterprise/T1567/"},{"key":"enterprise/T1572","id":"T1572","name":"Protocol Tunneling","page":"techniques/enterprise/T1572/"}],"data_path":"data/detection-rules/7cd1dcdc-6edf-4896-86dc-d1f19ad64903.json","kind":"sigma"}