Flash Player

1. What is Flash Player Fingerprinting

Flash Player, developed by Adobe, was a once-popular plugin used by browsers to render rich interactive content like games, videos, and animations.

Even though modern browsers like Chrome and Firefox no longer include or support Flash, many fingerprint detection frameworks — especially legacy ones — continue to look for:

• The presence of navigator.plugins["Shockwave Flash"]
• window.FlashCall, window.__flash__removeCallback, and related undocumented APIs
• MIME types like "application/x-shockwave-flash" in navigator.mimeTypes
• Behavior mimicking Flash-based plugins in JavaScript

This mismatch — a modern browser pretending to support Flash without native capability — can be used by detection systems to identify spoofed or automated browsers, particularly on platforms using old anti-cheat frameworks, legacy analytics tools, or old authentication flows (e.g., some Russian banking sites).

2. How Platforms Detect Flash Player Fingerprints

Despite being deprecated, platforms using older fingerprinting SDKs like FingerprintJS, Iovation, or FraudForce sometimes include Flash-related checks in their identification logic.

Common Flash Detection Methods include:

1. Plugin List Probing

• navigator.plugins['Shockwave Flash']
• navigator.plugins.length anomalies
  (e.g., expected Flash but not listed = suspicious)

2. Flash Version Detection

• plugins["Shockwave Flash"].description to extract “Flash 32.0.0.465”
• Often parsed for formatting, version, or vendor patterns

3. Window FlashBridge APIs (Flash-to-JS and vice versa)

• window.FlashCall, window.ExternalInterface.addCallback
• The presence of these APIs can indicate Flash emulation

4. MIME Type Analysis

• Attempts to detect "application/x-shockwave-flash" in list or availability
• Conflicts with real desktop browsers not supporting Flash anymore

5. Behavioral Detection

• Some systems inject custom JS that overwrites Function.toString() or Function.prototype
• To see if Flash APIs behave naturally or are faked

While Flash itself is blocked out-of-the-box in FlashID’s Chrome and Firefox-based profiles, merely missing Flash fingerprint data can raise red flags on platforms expecting it. This can lead to profile correlation discrepancies or browser behavior classification as non-human.

3. How FlashID Handles Flash Player Fingerprints

FlashID does not enable Flash Player in its profiles (based on Chrome and Firefox’s modern architecture).

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