{
  "family": "passwordfox",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nPasswordFox is a legitimate, commercially available password recovery utility developed by NirSoft. However, because it is designed to instantly extract and display user names and passwords stored by the Mozilla Firefox web browser in plain text, it is almost universally classified by security vendors as a \"HackTool\" or \"Riskware.\" Threat actors, particularly Initial Access Brokers and ransomware operators, heavily abuse PasswordFox, deploying it post-compromise to rapidly harvest local credentials.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nPasswordFox is not self-replicating malware. It is a standalone executable (`PasswordFox.exe`) that is typically dropped onto a system by an attacker who has already gained interactive access, or it is executed silently in the background by a malicious script or dropper Trojan.\n\nUpon execution, its capabilities are highly focused:\n<ul>\n<li><strong>Firefox Profile Parsing:</strong> The utility automatically locates the default Mozilla Firefox user profile directory on the local hard drive (e.g., `%APPDATA%\\Mozilla\\Firefox\\Profiles\\`).</li>\n<li><strong>Plain-Text Recovery:</strong> It decrypts the contents of the `logins.json` and `key4.db` (or older `signons.sqlite`) files. If the user has not set a \"Master Password\" in Firefox, PasswordFox will instantly display all stored website addresses, usernames, and passwords in clear text.</li>\n<li><strong>Command-Line Automation (Abuse):</strong> Attackers frequently abuse the tool's command-line interface. By executing `PasswordFox.exe /stext output.txt`, the tool runs completely silently, dumps all recovered passwords to a hidden text file, and closes, allowing the attacker to easily exfiltrate the file via a reverse shell.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nThe unauthorized execution of PasswordFox on a corporate endpoint is a critical indicator of an active credential harvesting operation. It signifies that an attacker has gained sufficient privileges to run credential-dumping tools and is actively seeking to escalate privileges or access cloud-based corporate resources using the victim's saved browser passwords.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Contextual Investigation:</strong> Determine if the execution was authorized by IT for legitimate password recovery. If not, the endpoint must be considered actively compromised and isolated immediately.</li>\n<li><strong>Trace the Execution:</strong> Utilize EDR telemetry to determine *how* PasswordFox was executed. Identify the parent process (e.g., `cmd.exe`, `powershell.exe`, or a malicious dropper) to locate the source of the breach.</li>\n<li><strong>Mandatory Global Credential Reset:</strong> If unauthorized execution is confirmed, all passwords stored in the user's browser, especially Active Directory or corporate web app credentials, must be reset immediately, as the attacker likely exfiltrated the plain-text results.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "HackTool.PasswordFox",
    "Riskware.PasswordViewer",
    "PWS.Nirsoft",
    "Tool.PasswordFox"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1555.003",
    "T1003",
    "T1059.003"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-02T07:28:51Z",
  "type": "HackTool / Riskware / Credential Stealer",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}