How Hackers Use PowerShell for Advanced Cyber Attacks: A Tale of Intrusion and Detection

In the world of cybersecurity, the battle between defenders and attackers is a relentless game of cat and mouse. With each new defense mechanism, adversaries evolve their tactics, techniques, and procedures (TTPs) to bypass traditional security controls. One of the most powerful weapons in the hacker’s arsenal? PowerShell. This simple tool, used for legitimate administrative tasks, has been weaponized by adversaries to silently compromise systems, move laterally, and escalate privileges.

Let’s dive into the world of a hacker using PowerShell to carry out an attack, step-by-step, using the MITRE ATT&CK framework to show how advanced detection rules can catch these malicious actions in real-time. This is a story of how a skilled hacker exploits PowerShell to break into a company’s network and how cutting-edge detection rules can thwart their plans.

The Initial Footprint: Reconnaissance and Weaponization

Our story begins with an attacker, “The Shadow”, who is looking to infiltrate the network of Acme Corp., a mid-sized financial firm. Armed with basic knowledge of the target and a well-crafted plan, The Shadow’s first goal is to gather critical information about the environment—without triggering any alarms.

1. Domain Admin Account Enumeration (T1071.001)

The Shadow begins by leveraging PowerShell to scan the domain for high-privilege accounts. Using commands like Get-ADUser and Get-ADGroup, they list out user accounts, focusing on administrative privileges. These reconnaissance steps, executed from within PowerShell, aim to identify domain admin accounts for later use. Without proper detection rules in place, these benign-looking PowerShell commands go unnoticed, allowing the attacker to create a map of the network’s most valuable targets.

2. Credentials from Password Stores (T1003.001)

After mapping out the accounts, The Shadow digs deeper, using PowerShell scripts to access cached credentials and password stores within Windows systems. With the help of tools like Get-Credentials or Invoke-Command, they harvest credentials that have been saved by users during previous logins. These credentials often reside in Windows Credential Manager or other protected stores. The Shadow doesn’t need to crack passwords—just leverage what’s already there.

Stage Two: Escalation and Lateral Movement

With privileged credentials in hand, The Shadow moves swiftly. PowerShell remains their tool of choice—stealthy, powerful, and capable of executing advanced attacks without raising alarms.

3. Powershell Execution From Registry Key (T1543.003)

Having obtained the credentials needed for escalation, The Shadow now needs to establish persistence on Acme Corp’s network. Using PowerShell, they create a malicious registry key to ensure that their PowerShell script is executed every time a system reboots. The registry is an ideal location for malware to reside undetected, allowing The Shadow to maintain access, even after a system restart.

4. Thread Memory Injection – PowerShell (T1086)

Now, The Shadow prepares for the next phase: exploiting system memory. Using PowerShell’s Invoke-Expression, they inject malicious code into the memory of a running process. This allows them to execute commands in the context of an already-running process, avoiding detection by traditional endpoint protection tools. At this stage, they can deploy additional payloads, pivot through the network, and maintain a stealthy presence within the system.

5. Webshell Recon Detection via CommandLine & Processes (T1505.003)

The Shadow is meticulous and cautious. Before they make any overt moves, they scan the system for potential webshells using PowerShell’s Get-Process and Get-WmiObject commands. These tools help them identify potential entry points and gain deeper access into the environment. Using command-line arguments, they remain invisible, avoiding any obvious network traffic that would alert defenders.

Stage Three: Exploitation and Command-and-Control

By now, The Shadow has established a foothold within Acme Corp’s network. They have the credentials, the system access, and the tools to escalate privileges and move across the network undetected. But there’s one thing left to do: executing the attack without triggering alarms.

6. PowerShell Exploit – Assembly Reflectively Loaded (T1106)

The Shadow uses a reflective DLL injection to exploit a vulnerability within the system, making it appear as if nothing suspicious is happening. Reflective loading of assemblies allows the attacker to inject a DLL into memory without needing to write it to disk—an approach that is difficult for traditional antivirus tools to detect. PowerShell becomes the perfect tool to load and execute the malicious code in memory, completely bypassing endpoint defenses.

7. Base64 Encoded Content Added to Registry (T1070.004)

To further evade detection, The Shadow encodes malicious PowerShell scripts in Base64 format. They store these encoded scripts in the Windows registry, an area typically overlooked by many security tools. This tactic ensures that their scripts are stored in an obfuscated manner, making it harder for defenders to identify the malicious payload.

Stage Four: Final Actions and Data Exfiltration

Now that The Shadow has administrative control over Acme Corp.’s network, they prepare for the final phase: data exfiltration.

8. PSExec Remote Connection (T1021.002)

Using PSExec, a well-known remote administration tool, The Shadow executes a series of commands on remote systems within Acme Corp.’s network. PowerShell scripts allow them to run these commands, often without raising suspicion. They exfiltrate sensitive financial data and credentials, using PowerShell to automate and accelerate the process.

9. WMIExec or SMBExec Remote Command Execution (T1047)

To complete the lateral movement and escalate further within the network, The Shadow also leverages WMIExec and SMBExec. These tools allow them to execute commands remotely across multiple machines without the need for additional payloads. PowerShell’s flexibility enables The Shadow to orchestrate these remote executions seamlessly.

How to Detect This Attack: The Role of Advanced Detection

As you can see, PowerShell is a versatile and powerful tool for attackers. However, it also leaves behind telltale signs that can be detected with the right advanced detection rules. At CyberStash, we’ve integrated these detection techniques into our Eclipse.XDR Cyber Defence Platform to identify malicious PowerShell activity:

1. Domain Admin Account Enumeration – Detects when attackers scan for privileged accounts.
2. Credential Harvesting from Password Stores – Flags suspicious credential access and extraction.
3. Registry-based Persistence – Monitors for unusual PowerShell executions or registry changes.
4. Memory Injection – Alerts on suspicious memory manipulation.
5. Reflective DLL Injection – Detects the execution of unregistered code in memory.
6. Webshell Activity – Flags unusual command-line behavior indicative of a webshell.
7. Obfuscated Scripts – Identifies base64 encoded or obfuscated PowerShell commands.
8. Remote Command Execution – Detects unusual remote execution methods like PSExec or WMIExec.

By leveraging CyberStash Eclipse.XDR’s advanced threat detection, we can ensure that attacks like the one The Shadow attempted don’t go unnoticed. Our multi-layered defense mechanism catches even the most sophisticated adversary tactics—whether they’re using PowerShell or any other tool in their arsenal.

In Conclusion: Proactive Detection is Key

As cyber adversaries grow more sophisticated, the need for proactive, multi-faceted detection has never been greater. Forensic Depth Analysis (FDA), combined with CyberStash Eclipse.XDR, offers a next-generation approach to threat detection—ensuring threats are identified early, validated with 100% certainty, and mitigated before they can do real damage.

The Shadow’s story is just one example of how PowerShell can be used to bypass traditional security mechanisms. With the right detection and response strategies in place, organizations can stay ahead of evolving cyber threats and protect their most valuable assets.

Ready to elevate your security? Contact CyberStash today to learn how our Eclipse.XDR platform can safeguard your organization from the next generation of cyber threats.