Browser Fingerprinting, Bot Detection 👨‍🔧

Here I study various aspects of existing evasion techniques to get around anti-bot systems. The technical findings that I am sharing below are based on observations of running web scraping scripts for a few months against websites protected by:

• Akamai Bot Manager by Akamai
• Advanced Bot Protection by Imperva (former Distil Networks)
• DataDome
• PerimeterX
• Shape Security

and a few other custom built (incl. social media platforms). Having troubles bypassing one of them?

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A ⭐ on this repo will be appreciated!

Technicalities

I constantly add stuff to this section. Over time I will try to make it look&feel more structured.

Random, maybe useful

• Cap FPS for Chromium with software rendering --use-gl=swiftshader - Limit CPU usage from SwiftShader by redraw freq. of Chromium in AVD
• Unlike some public comments on that matter chrome devtools protocol actually works on AVD-s with puppeteer
• Abusing GPU cache to create persistent tracking identifiers

puppeteer-extra-plugin-stealth 😈

✔️ Win / ❌ Fail / 🤷 Tie :

• ✔️ Client Hints - Shipped recently. In line with Chromium cpp implementation.
• ✔️ General navigator and window properties
• ✔️ Chrome plugins and native extensions - This includes both Widevine DRM extension, as well as Google Hangouts, safe-browsing etc.
• 🤷 p0f - detect host OS from TCP struct - Not possible to fix via Puppeteer APIs. Used in Akamai Bot Manager to match against JS and browser headers (Client Hints and User-Agent). There is a detailed explaination of the issue. The most reliable evasion seems to be not spoofing host OS at all, or using OSfooler-ng.
• 🤷 Browser dimensions - Although stealth plugin provides window.outerdimensions evasion, it won't work without correct config on non-default OS in headless mode; almost always fails when viewport size >= screen resolution (low screen resolution display on the host).
• ❌ core-estimator - This can detect mismatch between navigator.hardwareConcurrency and SW/WW execution profile. Not possible to limit/bump the ServiceWorker/WebWorker thread limit via existng Puppeteer APIs.
• ❌ WebGL extensions profiling - desc. tbd
• ❌ RTCPeerConnection when behind a proxy - Applies to both SOCKS and HTTP(S) proxies.
• ❌ Performance.now - desc. tbd (red pill)
• ❌ WebGL profiling - desc. tbd
• ❌ Behavior Detection - desc. tbd (events, params, ML+AI buzz)
• ❌ Font fingerprinting - desc. tbd (list+version+renderer via HTML&canvas)
• ❌ Network Latency - desc. tbd (integrity check: proxy det., JS networkinfo, dns resolv profiling&timing)
• ❌ Battery API - desc. tbd
• ❌ Gyroscope and other (mostly mobile) device sensors - desc. tbd

Multilogin, Kameleo and others 💰🤠

• ❌ General navigator and window properties - As per Multilogin documentation custom browser builds typically lag behind the latest additions added by browser vendors. In this case modified Chromium M7X is used (almost 10 versions behind when writing this).
• 🤷 Font masking - Font fingerprinting still leaks host OS due to use of different font rendering backends on Win/Lin/Mac. However, the basic "font whitelisting" technique can help to slightly rotate browser fingerprint.
• ❌ Inconsistencies - Profile misconfiguration leads to early property/behavior inconsitency detection.
• ❌ Native extensions - Unlike puppeteer-extra-plugin-stealth custom Chromium builds such as ML and Kameleo provide at most an override for native plugins and extensions shipped with Google Chrome.
• ❌ AudioContext APIs and WebGL property override - Manipulation of original canvas and audio waveform can be detected with custom JS.
• ✔️ Audio and GL noise

tbd (if you have an active subscription in any of these services and don't mind sharing an account drop me an email ❤️)

Available stealth browsers with automation features

Important You use this software at your own risk. Some of them contain malwares just fyi. I do not recommend using them.

Stealth Browser	Puppeteer	Selenium	Evasions	SDK/Tooling	Origin
GoLogin	✔️	✔️	🤮	👍	🇺🇸 + 🇷🇺
Incogniton	✔️	✔️	🤮	✔️	❓
ClonBrowser	✔️	✔️	🤮	✔️	❓
MultiLogin	✔️	✔️	🤮	✔️	🇪🇪 + 🇷🇺
Indigo Browser	✔️	✔️	🤮	✔️	❓
GhostBrowser	❌	❌	❌	👍	❓
Kameleo	✔️	✔️	🤮	✔️	❓
AntBrowser	❌	❌	❌	❌	🇷🇺
CheBrowser	❌	❌	🤮/✔️	👍	🇷🇺

Legend: 🤮 - Evasion based on noise. ❌ - No. ✔️ - Acceptable (with support libraries or not). 👍 - Very nice.

Non-technical notes

I need to make a general remark to people who are evaluating (and/or) planning to introduce anti-bot software on their websites. Anti-bot software is nonsense. Its snake oil sold to people without technical knowledge for heavy bucks.

Blocking bot traffic is based on the premise that you (or your technology provider) can distinguish bots from real users. To make this happen various privacy-invasive techniques are applied. To date none of them has been proved to be successful against specialized web scraping tools. Anti-bot software is all about reducing cheap bot traffic. It makes the process of scraping more expensive and complicated, but does not make it entirely impossible.

Anti-bot software vendors use detection techniques that fall into one of these two categories:

Binary detection

No specialized web scraping software is used. Vendor can detect the bad traffic based on information openly disclosed by the scraper e.g. User-Agent header, connection parameters etc.

As a result only bots that are not targeted to scrape specific website are blocked. This will make most of the managers happy, because the overall number of bad traffic goes down and it may almost look like there is no more bot traffic on the website. Wrong.

Traffic clustering

More advanced web scrapers make use of residential proxies and implement complex evasion techniques to fool anti-bot software to think that the web scraper is a real user. No detection mechanism exists to get around this due to technical limitation of web browsers.

In this case, most of the time the vendor will be only able to cluster the bad traffic by finding patterns in bot traffic and behavior. This is where browser fingerprinting comes into play. The problem with banning the traffic here is that it may turn out to be a risky operation when bots are successfully mimicking real users. There is a chance that by blocking bots the website will become unavailable to real visitors.

Gateways, captchas & co

If you think this is a way to go google "captcha resolve api".

Support

If you have problems with scraping specific website, write me a short email at [email protected]. Let's have a quick tête-à-tête consultation via Skype 😊.

Have I mentioned a ⭐ would be appreciated? :-)

➡️ Ethereum address 0x380a4b41fB5e0e1EB8c616eBD56f62f8F934Bab6