Cloudflared Portable Execution

Hunt Hypothesis

Detects the execution of the “cloudflared” binary from a non standard location.

Detection Rule

Sigma (Original)

title: Cloudflared Portable Execution
id: fadb84f0-4e84-4f6d-a1ce-9ef2bffb6ccd
status: test
description: |
    Detects the execution of the "cloudflared" binary from a non standard location.
references:
    - https://developers.cloudflare.com/cloudflare-one/connections/connect-networks/do-more-with-tunnels/trycloudflare/
    - https://github.com/cloudflare/cloudflared
    - https://www.intrinsec.com/akira_ransomware/
    - https://www.guidepointsecurity.com/blog/tunnel-vision-cloudflared-abused-in-the-wild/
    - https://github.com/cloudflare/cloudflared/releases
author: Nasreddine Bencherchali (Nextron Systems)
tags:
    - attack.command-and-control
    - attack.t1090.001
date: 2023-12-20
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\cloudflared.exe'
    filter_main_admin_location:
        Image|contains:
            - ':\Program Files (x86)\cloudflared\'
            - ':\Program Files\cloudflared\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate usage of Cloudflared portable versions
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessName endswith "\\cloudflared.exe" and (not((TargetProcessName contains ":\\Program Files (x86)\\cloudflared\\" or TargetProcessName contains ":\\Program Files\\cloudflared\\")))

Required Data Sources

Sentinel Table	Notes
`imProcessCreate`	Ensure this data connector is enabled

Cloudflared Portable Execution

Hunt Hypothesis

Detection Rule

Sigma (Original)

KQL (Azure Sentinel)

Required Data Sources

False Positive Guidance

MITRE ATT&CK Context

References