{
  "family": "sphinx",
  "sample_count": 2,
  "category": "trojan",
  "description": "Trojan:Win32/Sphinx is a sophisticated Info-Stealer and banking trojan, highly active in targeting financial institutions and cryptocurrency platforms. While it shares some conceptual similarities with older trojans like Zeus, Sphinx operates as a modern, evasive data harvesting tool. It focuses on stealing credentials, session cookies, and financial data by injecting malicious code directly into the user's web browser, effectively performing Man-in-the-Browser (MitB) attacks.<br><br><b>Understanding Sphinx (Info-Stealers)</b><br>To an end-user, the infection is entirely invisible. They log into their bank normally, unaware that Sphinx is silently intercepting their keystrokes and modifying the web page to request additional, fraudulent information (like ATM PINs). For a security analyst, a Sphinx infection represents a critical, immediate breach of highly sensitive credentials and requires a rapid response to prevent financial fraud (`T1111`).<br><br><b>Execution and Espionage Mechanics</b><br>Sphinx is predominantly distributed through highly targeted malspam campaigns (`T1566.001`), often using weaponized Office documents. Upon execution, Sphinx establishes persistence (typically via Registry Run keys - `T1547.001`) and aggressively injects its core DLL payload into running browser processes (like `chrome.exe` or `firefox.exe`) using advanced process hollowing or atom bombing techniques (`T1055`). Once injected, it intercepts API calls related to network communication, allowing it to read all HTTPS traffic in cleartext. It captures login credentials (`T1056.001`), scrapes session cookies (`T1539`), and actively injects fraudulent HTML forms into targeted banking portals (Web Injects - `T1185`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact is immediate, devastating financial fraud and credential theft. Host-based IoCs include EDR alerts for 'Suspicious Process Injection' specifically targeting browser executables. The creation of unexpected, randomly named DLLs in the `%AppData%` directory is common. Network IoCs involve the malware beaconing to C2 servers using custom, often encrypted protocols over port 80/443 to receive updated 'web inject' configuration files and to exfiltrate stolen data.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Sphinx and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Sphinx is classified as a Trojan. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments."
      }
    },
    {
      "@type": "Question",
      "name": "How does Sphinx establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Sphinx typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks."
      }
    },
    {
      "@type": "Question",
      "name": "What are the essential incident response steps for mitigating a Sphinx compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Sphinx should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups."
      }
    },
    {
      "@type": "Question",
      "name": "What secondary payloads and staging behaviors are commonly associated with Sphinx?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Sphinx frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors."
      }
    },
    {
      "@type": "Question",
      "name": "How can security operations teams effectively detect and hunt for Sphinx across enterprise endpoints?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Defenders should hunt for Sphinx by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1111",
    "T1056.001",
    "T1055",
    "T1185"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1185",
      "name": "Browser Session Hijacking (Man-in-the-Browser web injects)",
      "tactic": "Collection"
    },
    {
      "id": "T1055",
      "name": "Process Injection (Injecting into browser processes to steal data)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1111",
      "name": "Two-Factor Authentication Interception (Stealing session cookies to bypass 2FA)",
      "tactic": "Credential Access"
    },
    {
      "id": "T1056.001",
      "name": "Input Capture: Keylogging",
      "tactic": "Collection"
    }
  ],
  "containment_steps": [
    "Immediately isolate the infected endpoint to halt the active exfiltration of banking credentials and session cookies.",
    "Mandate an immediate password reset for the compromised user, prioritizing banking, cryptocurrency, and corporate SSO accounts.",
    "Force a session token revocation (log out of all active sessions) for the user across all critical SaaS applications and internal portals.",
    "Analyze EDR telemetry to identify the initial infection vector (e.g., the specific phishing email) to protect other users."
  ],
  "what_to_avoid": [
    "Do not trust that 2FA will protect the user's accounts; Sphinx steals active session cookies, which bypasses the need for 2FA.",
    "Avoid relying solely on manual file deletion; the injected browser processes must be terminated, and the persistence mechanisms removed."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "execution",
    "persistence"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows 7"
  ]
}