What is a Stager in Cybersecurity?

Published: June 4, 2025

Written by: Lizzie Danielson


A stager is a small piece of malicious software that attackers use to start a larger cyberattack. Think of it as a cybercriminal’s “knock on the door”—it’s not the main threat, but it opens the way for more dangerous malware to follow.

How a stager works

Attackers deliver stagers in several ways, usually through phishing emails, malicious websites, or by taking advantage of software flaws. Once the stager lands on a device, it does three main things:

  • Connects to the attacker’s remote server

  • Downloads a bigger, more powerful piece of malware (called the payload)

  • Runs the payload to give the attacker greater control

Splitting the attack into steps helps cybercriminals hide what they’re doing, making it tougher for security tools to spot all the bad activity right away.


Why threat actors use stagers

Stagers are popular for some good (bad) reasons:

  • Stealth: Small bits of code slip past many security tools unnoticed

  • Flexibility: Attackers can choose which payload to deliver after the stager is on your system

  • Bypassing detection: Multi-stage attacks trick antivirus and monitoring systems


The role of command-and-control servers

Once the stager is running, it connects to a Command-and-Control (C2) server controlled by the attacker. Through this connection, the attacker can:

  • Send the main payload

  • Push updates or new commands

  • Pull stolen information from the infected device

Essentially, your system can become one small piece of a much larger criminal network.


Examples of malware that use stagers

Stagers show up in many advanced attacks and well-known tools, such as:

  • Meterpreter (seen in Metasploit)

  • Cobalt Strike

  • Remote Access Trojans (RATs)

  • Advanced Persistent Threat (APT) toolkits

Red teams use them for simulations, but attackers use them to cause real harm too. Read more about proliferating RATS, evolving ransomware threats, and other findings in the Huntress 2025 Cyber Threat Report.


How to defend against stagers

Nobody’s immune, but solid cyber hygiene makes a big difference:

  • Install and update antivirus software. Look for tools that analyze the behavior of files, not just their names or signatures.

  • Patch your operating system and apps as soon as updates are available.

  • Be careful with email attachments and suspicious links—even if they seem to come from trusted contacts.

  • Watch for strange outbound traffic, especially connections to unknown servers.


Closing thoughts

Stagers are just the beginning of bigger attacks. By keeping an eye out for these early warning signs, you’ll make it much harder for cybercriminals to get a foothold in your systems.