Port 1777: PowerGuardian — A Registered Port with an Untold Story

What Range This Port Belongs To

Port 1777 falls in the registered ports range (1024-49151), the middle tier of the port numbering system.

The three tiers work like this:

• Well-known ports (0-1023): Reserved for foundational Internet services. SSH, HTTP, HTTPS, DNS. These require root or administrator privileges to bind on most operating systems.
• Registered ports (1024-49151): Available for applications to register with IANA. No privilege required to bind, but the registry exists so vendors can stake a claim and avoid collisions.
• Dynamic/ephemeral ports (49152-65535): Handed out temporarily to client connections. Your browser uses one of these as the source port when connecting to a server.

Registered doesn't mean well-known. It means someone filed a form.

The Official Assignment: PowerGuardian

According to IANA's Service Name and Transport Protocol Port Number Registry, port 1777 is assigned to powerguardian, registered on 2008-08-29.¹

That's the entire public record.

No RFC. No specification. No company name. No description of what the protocol does or what problem it solves. The registration exists as a single row in a database: a name, a port number, a date.

Community discussion from the early 2010s shows network administrators noticing "powerguardian" appearing in their router logs and being unable to find documentation anywhere.² The most likely explanation, based on the name and registration era, is that it belongs to some form of power management or UPS (uninterruptible power supply) monitoring software, possibly from a vendor who registered the port informally. But this is inference, not fact.

If you're seeing port 1777 traffic on your network, the PowerGuardian registration offers almost no guidance.

The Other History: Scarab

Port 1777 also appears in older security databases associated with the Scarab trojan, a piece of malware that used this port for command-and-control communications.³

Scarab is largely a historical footnote now. The threat predates the 2008 PowerGuardian registration, which means the port has worn two identities: first malware, then mystery software. Neither left much of a trace.

If you see unexpected traffic on port 1777 today, treat it as worth investigating, but don't assume malice. The Scarab variants that used this port are not active threats in 2026.

How to Check What's Listening on This Port

If port 1777 shows up on a machine you manage, these commands will tell you what's behind it:

Linux/macOS:

# Show what process is listening on port 1777
sudo ss -tlnp | grep 1777

# Alternative using lsof
sudo lsof -i :1777

Windows:

# Show listening port with associated PID
netstat -ano | findstr :1777

# Identify the process by PID
tasklist /fi "PID eq <PID>"

Network-wide (with nmap):

nmap -sV -p 1777 <target-ip>

The process name is usually more informative than the port number.

Why Unassigned and Obscure Ports Matter

The Internet runs on shared conventions. When port 443 opens, the world knows to speak HTTPS. That shared knowledge is what makes the port system work.

Obscure registered ports like 1777 reveal the edges of that convention. The registry has over 11,000 entries. Many were filed once and never documented publicly. Software vendors register ports to avoid collisions, then ship products, and the documentation never makes it to public RFCs.

The result is a registry that's technically authoritative but practically incomplete. Port 1777 is registered. It has a name. And that's nearly all anyone outside the original vendor has ever known about it.