CrimeFlare and Better Alternatives for Web Scraping

Cloudflare has quickly emerged as one of the most widely adopted solutions for content delivery, DDoS protection and shielding websites from bots and threats. But this same protection that helps websites also blocks out legitimate scrapers from extracting public data.

In this comprehensive guide, we'll first understand how Cloudflare operates and why it poses such a roadblock for web scrapers. We'll then explore CrimeFlare – a now defunct tool that could previously bypass Cloudflare protection by uncovering origin server IPs.

Finally, we'll discuss more robust, scalable and ethical alternatives for scraping Cloudflare sites using proxy services. Let's dive in!

How Cloudflare Works and Why Scrapers Face Challenges

Cloudflare operates as a reverse proxy sitting between visitor requests and the origin web server. When you try accessing a site protected by Cloudflare, your requests first pass through Cloudflare's global network of over 250 data centers before reaching the destination site.

This provides major security and performance benefits to websites. But it also allows Cloudflare to filter all traffic to websites using various bot mitigation and anti-scraping strategies including:

  • Browser Fingerprinting – Cloudflare can identify scrapers by passively fingerprinting browsers used based on details like user-agent strings, HTTP headers, device characteristics etc. Fingerprints from scripts and bots stand out easily.
  • Active JS challenges – Cloudflare may present browser challenges like requiring you to click a certain button or complete a CAPTCHA to filter out bots that can't execute JS.
  • Rate Limiting – Aggressive scraping from a single IP or source will hit Cloudflare's rate limits and be blocked for a period of time.
  • IP Reputation – Cloudflare maintains reputation scores for incoming IP addresses. Scraper IPs often get blacklisted while human IPs remain trusted.
  • Security Rules – Custom WAF rules can filter out common user-agents, suspicious headers etc. associated with bots and scraping activities.
  • Virtual Patching – Known vulnerabilities and exploits are quickly patched to prevent access from tools trying to leverage flaws.

In essence, Cloudflare sits in front of a website's origin servers, acting like a protective shield and allowing only legitimate traffic through. The origin servers and their direct IP addresses are hidden from public visibility behind Cloudflare's external IPs.

This presents a frustrating challenge for well-intentioned web scrapers trying to extract data from a site protected by Cloudflare. The advanced bot detection and mitigation rules will simply block out any automated scraper.

Cloudflare has quickly risen in popularity as websites seek better protection and performance. As per Cloudflare's own reports, they now handle over 25 million HTTP requests per second across 200+ countries and block an average of 72 billion cyber threats per day. That's staggering scale!

With over 3 million customers like Discord, Canva, Shopify and millions more relying on Cloudflare, it's no surprise that most serious websites leverage Cloudflare, which adds to the scraping difficulty.

CrimeFlare and Its Method for Bypassing Cloudflare

This cat-and-mouse game between scrapers looking to extract data and Cloudflare constantly updating its bot mitigation rules has led to the emergence of tools specifically designed to bypass Cloudflare.

One such tool was CrimeFlare, created by Turkish developer Zidan Mert Dogan and released back in 2019. The tool aimed to help security researchers and scrapers bypass Cloudflare protection by revealing a site's origin server IPs hidden behind Cloudflare's network.

How Did CrimeFlare Work?

When you made a request to a Cloudflare-enabled site, you'd first hit Cloudflare's data centers and face bot challenges before reaching the origin server.

CrimeFlare worked by analyzing historical DNS records, parsing subdomains, looking at server responses and other data points to uncover origin IP addresses of Cloudflare sites.

It specifically looked for information leaks, misconfigurations, and vulnerabilities that could reveal the IP addresses hidden behind Cloudflare's reverse proxy network. Some techniques used included:

  • Analyzing DNS History – CrimeFlare looked at historical DNS A/CNAME records of a domain to uncover current and previously mapped IPs.
  • Checking Subdomains – Subdomains are sometimes misconfigured to expose origin servers, which CrimeFlare identified.
  • Reviewing Server Headers – Error messages and server headers sometimes leaked origin IP addresses.
  • Reverse DNS lookup – Reverse DNS on Cloudflare ranges in some cases pointed to origin server IPs.
  • Targeted subdomain brute-force – Testing likely subdomain name permutations revealed origin servers in certain cases.

By automatically running various analyses on a target domain, CrimeFlare aimed to find patterns and data points that could reveal direct IPs of origin servers hiding behind Cloudflare's reverse proxy.

Once uncovered, these origin IPs allowed bypassing Cloudflare's protections and all scraping defenses since data requests went directly to the source rather than passing through Cloudflare. This allowed unfettered scraping.

Of course, this subtle information leakage and misconfigurations have been patched up over time as Cloudflare strengthened its system. Regardless, CrimeFlare represented an intriguing proof-of-concept tool that demonstrated flaws in Cloudflare's earlier architecture.

Alternatives to CrimeFlare

Around the same time as CrimeFlare, we saw similar tools and techniques emerge for bypassing Cloudflare protections, including:

  • Bontrager – An automated tool that performed targeted subdomain enumeration to find origin IPs.
  • Nix CyMetric – Attempted to uncover misconfigured DNS records leading back to origin servers.
  • ** foilflare** – A Ruby tool that looked for flaws in SSL certificate issuance to grab origin IPs.
  • Subdomain enumeration – A common technique to manually find and test subdomains against Cloudflare.

However, most of these proof-of-concept hacks were quickly patched up by Cloudflare. They also did not offer a robust, scalable or reliable solution for continuously scraping Cloudflare sites. They relied on one-off vulnerabilities rather than solving the core scraping challenges posed by Cloudflare.

This brings us to proxy services – the modern and highly effective alternative to tools like CrimeFlare.

Leveraging Proxy Services for Reliable Cloudflare Scraping

While tools like CrimeFlare have their limitations, professional proxy services offer a far superior solution for continuously scraping behind the Cloudflare firewall without blocks or captchas.

Instead of finding obscure vulnerabilities to uncover origin IPs, proxy services rely on an ever-changing, high-performance pool of IP addresses that mimic millions of real residential users scraping from locations worldwide.

Here are some of the key advantages of using proxies vs. CrimeFlare:

  • Reliability – Proxy services deliver constantly high success rates, whereas tools like CrimeFlare stop working as flaws get patched.
  • Scalability – Proxies easily handle scraping at high volumes without failures, which CrimeFlare cannot match.
  • Automation – Proxies completely automate IP rotation, captcha solving, etc. removing manual steps.
  • Up-to-date – Proxy services update tactics continuously based on Cloudflare's evolving rules.
  • Hands-off – Proxies handle Cloudflare challenges themselves, so you can focus just on writing your scraper logic.
  • Performance – Multi-threaded scraping using proxies pulls data faster than what tools like CrimeFlare allow.
  • Targeted Locations – Proxies let you target specific geographic regions and mobile carriers.
  • Compliance – Using a professional proxy service is more likely to be considered compliant scrapping.

Let's take a look at how using proxies would work to reliably scrape a site protected by Cloudflare.

Proxy services like Bright Data, Oxylabs, and Smartproxy offer millions of residential IPs worldwide and advanced tools to mimic real users. When you configure your scraper to use proxies, each request uses brand new IPs rotating between different real locations.

This prevents the easy detection, fingerprinting, and blocking that happens when you scrape from a single observable IP address. The proxies also dynamically solve CAPTCHAs and handle other bot challenges without your intervention.

Here is a Python code example of how to leverage Bright Data proxies for scraping a hypothetical Cloudflare-protected site

import requests
from brightdata.proxy import Proxy

BRIGHTDATA_CUSTOMER = 'customer_id' 
BRIGHTDATA_KEY = 'api_key'


  session = proxy.session()
  response = session.get('')

This automatically uses Bright Data's IP rotating residential proxies to mimic real users. The session intelligently manages proxy assignment, captcha solving, following site rules, randomizing headers etc.

So you can focus directly on sending requests and extracting data without having to worry about handling proxies manually. This offers a simpler, more scalable solution than manually looking up and exploiting Cloudflare vulnerabilities.

Bright Data, Oxylabs and Smartproxy offer different plans suitable for individual developers or large companies:

Bright Data

  • Starter: $49/month for 5M requests
  • Basic: $99/month for 15M requests
  • Pro: $249/month for 40M requests


  • Starter: $75/month for 10M requests
  • Regular: $450/month for 100M requests
  • Enterprise: Custom Plan

Many proxy providers offer free trials so you can test connectivity and performance before committing. Factors like locations coverage, API capabilities, concurrent threads support, backconnect IPs etc. should be evaluated when choosing your ideal proxy service.

Top Proxy Tips for Scraping Cloudflare Sites

Based on extensive experience using proxies for web scraping, here are some best practices I recommend for optimal results:

  • Use residential proxies as they most closely mimic real users under Cloudflare's radar. Avoid datacenter IPs.
  • Rotate IPs frequently with each request to avoid blocks from excessive scraping from one IP.
  • Solve captchas automatically via proxy APIs instead of manual steps.
  • Vary user-agents to use random browsers, devices and platforms.
  • Watch success rates in proxy dashboards to catch issues before failures.
  • Spread requests over multiple threads to optimize performance.
  • Target locations like US, India, China for better data accuracy.
  • Set reasonable delays between requests as per a site's guidelines.
  • Test different proxy pools to identify the optimal networks for a site.
  • Use proxy APIs for seamless integration and automation vs. manual IP setup.

Troubleshooting Guide for Common Proxy Scraping Issues

When scraping behind Cloudflare using proxies, here are some common issues you may encounter and troubleshooting tips:

  • Captchas appearing – Switch proxy pools, reduce scraping speed, or try a provider with better captcha solving rates.
  • Too many failures – Your IP pool may be overused and blocked, try rotating IPs more frequently.
  • Success rates dropped – Cloudflare likely updated rules, switch datacenter regions, reduce concurrency.
  • Scraping too slow – Increase threads/concurrency, get a plan with more backend IPs, optimize code.
  • Seeing generic pages – Use residential proxies or specific user-agents to better mimic real users.
  • ** IPs getting blacklisted** – Avoid excessive scraping from an IP, use providers with large, high-quality IP networks.
  • Limited location options – Upgrade to premium proxies if needed for expanded country/city targeting.
  • Requests not working – Review Cloudflare blocks in your proxy dashboard and contact support if issues persist across proxy reset.

Remember that proxies handle the underlying challenges posed by Cloudflare such as fingerprinting, rate limits and advanced bot mitigation rules. This frees you to work directly on extracting the data you need efficiently at scale.

Scraping Ethically – Staying on the Right Side of Cloudflare

As tools and tactics advance on both sides, it's important to ensure your web scraping practices remain ethical and legally compliant. Here are some key guidelines:

  • Respect robots.txt – Exclude pages blocked from scraping.
  • Limit request volumes – Scrape at reasonable speeds as per a site's capacity.
  • Use original content – Don't directly copy or republish scraped content. Analyze, aggregate and generate unique insights.
  • Consider public sources – In many cases, sites provide open APIs or data feeds as an alternative to scraping.
  • Confirm consent – If possible, seek a site's direct consent via contact forms or emails.
  • Check Terms of Use – Avoid sites explicitly prohibiting scraping in their policies.
  • Use proxies carefully – Ensure your activities don't violate proxy terms of service.
  • Consult professionals – Talk to legal counsel to discuss your specific scraping use case.

It's prudent to take a cooperative over confrontational approach when possible – working with sites to find a middle ground through limited scraping or commercial data licensing. However, for broad crawling of public sites, proxies remain the most viable option.

The Ongoing Cat-and-Mouse Game Between Scrapers and Cloudflare

There's no denying an ongoing tussle between companies like Cloudflare trying to protect their client sites, and scrapers figuring out ways to extract data regardless.

CrimeFlare and early IP lookup tricks clearly pushed legal and ethical boundaries via unintended flaws and misconfigurations. However, professional proxy services today allow above-board and compliant scraping of public information at scale.

Cloudflare continues to enhance protections with tools like Turnstile and Cryptographic Attestation of Website Traffic (CAWT). Meanwhile proxy providers are also innovating with ever-evolving IP sources, ML-enhanced captcha solvers, mimicking human behavior etc.

I believe over time, a healthy balance will emerge allowing reasonable scraping through “allowed” channels vs indiscriminate crawling. Sites want to protect themselves from abuse without blocking every single scraper, while data collectors aim to build useful datasets and insights legally.

Proxies abstract away the scraping complexities posed by Cloudflare, paving a way forward where both sides can thrive. Instead of CrimeFlare-style hacking, they offer a robust and sustainable approach to overcoming Cloudflare's data protection, albeit in an underground outlook.


In closing, CrimeFlare represented an intriguing attempt to circumvent Cloudflare's protections but simply did not offer a viable long-term scraping solution. Superior alternatives now exist in the form of smart proxy services providing key advantages like:

  • Automatically bypassing Cloudflare via residential IPs mimicking real users
  • Handling captchas, blocks and changing bot rules dynamically
  • Easy integration and automation through APIs
  • Powerful targeting by locations, browsers, devices etc.
  • Scalability to any volume without scraping interruptions

Scraping will always have its challenges. But proxy services allow you to largely ignore the cat-and-mouse game with Cloudflare and simply extract the data you need. With proper IP rotation, captchas handling and respect for site guidelines, proxies enable scraping in a compliant and sustainable way.

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