RDP to HTTP or HTTPS Target Ports

Hunt Hypothesis

Detects svchost hosting RDP termsvcs communicating to target systems on TCP port 80 or 443

Detection Rule

Sigma (Original)

title: RDP to HTTP or HTTPS Target Ports
id: b1e5da3b-ca8e-4adf-915c-9921f3d85481
status: test
description: Detects svchost hosting RDP termsvcs communicating to target systems on TCP port 80 or 443
references:
    - https://twitter.com/tekdefense/status/1519711183162556416?s=12&t=OTsHCBkQOTNs1k3USz65Zg
    - https://www.mandiant.com/resources/bypassing-network-restrictions-through-rdp-tunneling
author: Florian Roth (Nextron Systems)
date: 2022-04-29
modified: 2022-07-14
tags:
    - attack.command-and-control
    - attack.t1572
    - attack.lateral-movement
    - attack.t1021.001
    - car.2013-07-002
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Image|endswith: '\svchost.exe'
        Initiated: 'true'
        SourcePort: 3389
        DestinationPort:
            - 80
            - 443
    condition: selection
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imNetworkSession
| where (SrcProcessName endswith "\\svchost.exe" or DstProcessName endswith "\\svchost.exe") and NetworkDirection =~ "true" and SrcPortNumber == 3389 and (DstPortNumber in~ ("80", "443"))

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Command and Control
• Tactic: Lateral Movement
• Technique: T1572 — T1572
• Technique: T1021.001 — T1021.001

References

• https://twitter.com/tekdefense/status/1519711183162556416?s=12&t=OTsHCBkQOTNs1k3USz65Zg
• https://www.mandiant.com/resources/bypassing-network-restrictions-through-rdp-tunneling
• SigmaHQ Rule