Malicious Reverse Tunnel Agent Execution with Hidden Server Flags

ATT&CK techniques

C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1572Protocol Tunneling
Exfiltration
Impact

What it detects

This rule detects execution of agent.exe with -server and -hide command-line flags, the reverse tunnel implant used in a Huntress-investigated Nightmare-Eclipse intrusion that connected to staybud.dpdns.org over port 443. The -hide flag conceals the agent window while -server points to the attacker relay, establishing a yamux-based reverse tunnel. This flag combination reflects covert command-and-control tunneling.

Reporting behind it

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Malicious Cloudflared Tunnel Established with Token

Malicious Reverse Tunnel Agent Execution with Hidden Server Flags

Pivot detection · T1572 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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