Potential Masquerading as Browser Process

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Identifies suspicious instances of browser processes, such as unsigned or signed with unusual certificates, that can indicate an attempt to conceal malicious activity, bypass security features such as allowlists, or trick users into executing malware.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*

Severity: low

Risk score: 21

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Defense Evasion
  • Tactic: Persistence
  • Rule Type: BBR
  • Data Source: Elastic Defend

Version: 2

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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process where host.os.type == "windows" and event.type == "start" and
  (
    /* Chrome Related Processes */
    (process.name : (
      "chrome.exe", "GoogleUpdate.exe", "GoogleCrashHandler64.exe", "GoogleCrashHandler.exe",
      "GoogleUpdateComRegisterShell64.exe", "GoogleUpdateSetup.exe", "GoogleUpdateOnDemand.exe",
      "chrome_proxy.exe", "remote_assistance_host.exe", "remoting_native_messaging_host.exe",
      "GoogleUpdateBroker.exe"
     ) and not
      (process.code_signature.subject_name : ("Google LLC", "Google Inc") and process.code_signature.trusted == true)
     and not
      (
        process.executable : (
          "?:\\Program Files\\HP\\Sure Click\\servers\\chrome.exe",
          "?:\\Program Files\\HP\\Sure Click\\*\\servers\\chrome.exe"
        ) and
        process.code_signature.subject_name : ("Bromium, Inc.") and process.code_signature.trusted == true
      ) and
     not (
       process.executable : (
         "?:\\Users\\*\\AppData\\Local\\ms-playwright\\chromium-*\\chrome-win\\chrome.exe",
         "?:\\Users\\*\\AppData\\Local\\Programs\\synthetics-recorder\\resources\\local-browsers\\chromium-*\\chrome-win\\chrome.exe",
         "*\\node_modules\\puppeteer\\.local-chromium\\win64-*\\chrome-win\\chrome.exe",
         "?:\\Program Files (x86)\\Invicti Professional Edition\\chromium\\chrome.exe",
         "?:\\Program Files\\End2End, Inc\\ARMS Html Engine\\chrome.exe",
         "?:\\Users\\*\\AppData\\Local\\*BurpSuitePro\\burpbrowser\\*\\chrome.exe",
         "?:\\Users\\*\\AppData\\Roaming\\*BurpSuite\\burpbrowser\\*\\chrome.exe"
       ) and process.args: (
               "--enable-features=NetworkService,NetworkServiceInProcess",
               "--type=crashpad-handler", "--enable-automation", "--disable-xss-auditor"
             )
     )
    ) or

    /* MS Edge Related Processes */
    (process.name : (
      "msedge.exe", "MicrosoftEdgeUpdate.exe", "identity_helper.exe", "msedgewebview2.exe",
      "MicrosoftEdgeWebview2Setup.exe", "MicrosoftEdge_X*.exe", "msedge_proxy.exe",
      "MicrosoftEdgeUpdateCore.exe", "MicrosoftEdgeUpdateBroker.exe", "MicrosoftEdgeUpdateSetup_X*.exe",
      "MicrosoftEdgeUpdateComRegisterShell64.exe", "msedgerecovery.exe", "MicrosoftEdgeUpdateSetup.exe"
     ) and not
      (process.code_signature.subject_name : "Microsoft Corporation" and process.code_signature.trusted == true)
     and not
      (
        process.name : "msedgewebview2.exe" and
        process.code_signature.subject_name : ("Bromium, Inc.") and process.code_signature.trusted == true
      )
    ) or

    /* Brave Related Processes */
    (process.name : (
      "brave.exe", "BraveUpdate.exe", "BraveCrashHandler64.exe", "BraveCrashHandler.exe",
      "BraveUpdateOnDemand.exe", "brave_vpn_helper.exe", "BraveUpdateSetup*.exe",
      "BraveUpdateComRegisterShell64.exe"
     ) and not
      (process.code_signature.subject_name : "Brave Software, Inc." and process.code_signature.trusted == true)
    ) or

    /* Firefox Related Processes */
    (process.name : (
      "firefox.exe", "pingsender.exe", "default-browser-agent.exe", "maintenanceservice.exe",
      "plugin-container.exe", "maintenanceservice_tmp.exe", "maintenanceservice_installer.exe",
      "minidump-analyzer.exe"
     ) and not
      (process.code_signature.subject_name : "Mozilla Corporation" and process.code_signature.trusted == true)
     and not
      (
        process.name : "default-browser-agent.exe" and
        process.code_signature.subject_name : ("WATERFOX LIMITED") and process.code_signature.trusted == true
      )
    ) or

    /* Island Related Processes */
    (process.name : (
      "Island.exe", "IslandUpdate.exe", "IslandCrashHandler.exe", "IslandCrashHandler64.exe",
      "IslandUpdateBroker.exe", "IslandUpdateOnDemand.exe", "IslandUpdateComRegisterShell64.exe",
      "IslandUpdateSetup.exe"
     ) and not
      (process.code_signature.subject_name : "Island Technology Inc." and process.code_signature.trusted == true)
    ) or

    /* Opera Related Processes */
    (process.name : (
      "opera.exe", "opera_*.exe", "browser_assistant.exe"
     ) and not
      (process.code_signature.subject_name : "Opera Norway AS" and process.code_signature.trusted == true)
    ) or

    /* Whale Related Processes */
    (process.name : (
      "whale.exe", "whale_update.exe", "wusvc.exe"
     ) and not
      (process.code_signature.subject_name : "NAVER Corp." and process.code_signature.trusted == true)
    ) or

    /* Chromium-based Browsers processes */
    (process.name : (
      "chrmstp.exe", "notification_helper.exe", "elevation_service.exe"
     ) and not
      (process.code_signature.subject_name : (
        "Island Technology Inc.",
        "Citrix Systems, Inc.",
        "Brave Software, Inc.",
        "Google LLC",
        "Google Inc",
        "Microsoft Corporation",
        "NAVER Corp.",
        "AVG Technologies USA, LLC",
        "Avast Software s.r.o."
       ) and process.code_signature.trusted == true
      )
    )
  )

Framework: MITRE ATT&CKTM