{
  "family": "powerun",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nPowerun (often detected as HackTool.Powerun, Riskware.PowerShell, or Trojan.Powerun) is not a standalone malware family, but rather a detection signature for malicious wrappers or execution utilities designed to covertly run PowerShell scripts. Threat actors use Powerun utilities to bypass local execution policies, obfuscate their malicious PowerShell payloads, and execute fileless attacks that evade traditional antivirus scanning.\n\n<h3>Technical Architecture and Exploitation</h3>\nPowerShell is a highly powerful, legitimate administrative framework built into Windows. Because it is a trusted tool, attackers heavily favor it for \"Living off the Land\" (LotL) attacks.\n\nThe \"Powerun\" classification typically applies to utilities that facilitate this abuse:\n<ul>\n<li><strong>Execution Policy Bypass:</strong> By default, Windows restricts the execution of unsigned PowerShell scripts. Powerun tools often execute PowerShell using the `-ExecutionPolicy Bypass` flag or instantiate the PowerShell runspace directly within a custom C# or C++ executable to completely ignore local Group Policy restrictions.</li>\n<li><strong>Obfuscation and Fileless Execution:</strong> Powerun wrappers frequently decode heavily obfuscated (Base64) PowerShell scripts and execute them directly in memory (`-EncodedCommand`). This means the actual malicious payload never touches the hard drive, rendering static disk scanning ineffective.</li>\n<li><strong>AMSI Evasion:</strong> Advanced Powerun utilities attempt to patch or disable the Anti-Malware Scan Interface (AMSI) in memory before executing the PowerShell script, blinding the EDR solution to the script's contents.</li>\n</ul>\n\n<h3>Threat Impact</h3>\nA Powerun detection is a critical indicator of compromise. It signifies that an attacker is actively attempting to execute arbitrary code on the system utilizing trusted system binaries. The payloads executed via Powerun are frequently Cobalt Strike beacons, Empire agents, or ransomware stagers.\n\n<h3>Defense and Resilience Strategies</h3>\n<ul>\n<li><strong>Constrained Language Mode (CLM):</strong> The most effective defense against malicious PowerShell usage is enforcing Constrained Language Mode via Windows Defender Application Control (WDAC). CLM severely restricts the APIs and COM objects that PowerShell can access, neutralizing most offensive scripts.</li>\n<li><strong>Script Block Logging:</strong> Enable PowerShell Script Block Logging (Event ID 4104). This forces the OS to log the *de-obfuscated* content of the script as it executes, providing invaluable telemetry for incident responders.</li>\n<li><strong>Behavioral Monitoring:</strong> Monitor EDR telemetry for suspicious parent-child process relationships, such as Word (`winword.exe`) or Excel (`excel.exe`) unexpectedly spawning `powershell.exe` with encoded command-line arguments.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "HackTool.Powerun",
    "Riskware.PowerShellRunner",
    "Trojan.Powerun"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1059.001",
    "T1222.001",
    "T1562.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-01T16:50:17Z",
  "type": "HackTool / Riskware",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}