• Skip to primary navigation
  • Skip to main content
  • Skip to footer

Cisco Umbrella

Enterprise network security

  • Free Trial
  • Contact us
  • Blog
  • Login
    • Umbrella Login
    • Cloudlock Login
  • Products
    • Product
      • Cisco Umbrella Cloud Security Service
      • Cisco Umbrella Investigate
      • Product Packages
      • Support Packages
    • Functionality
      • DNS-Layer Security
      • Secure Web Gateway
      • Cloud Access Security Broker (CASB)
      • Interactive Intelligence
      • Cloud-Delivered Firewall
    •  
    • Webinar signup
  • Solutions
    • By Need
      • Protect Mobile Users
      • Fast Incident Response
      • Web Content Filtering
      • Shadow IT Discovery & App Blocking
      • Unified Threat Enforcement
      • Reduce Security Infections
      • Secure Direct Internet Access
      • Securing Remote and Roaming Users
    • By Network
      • Protect Guest Wi-Fi
      • SD-WAN Security
      • Off-Network Endpoint Security
    • By Industry
      • Higher Education Security
      • K-12 Schools Security
      • Healthcare, Retail and Hospitality Security
      • Enterprise Cloud Security
      • Small Business Cybersecurity
      • Our Customers
      • Customer Stories
    • Ransomware Defense for Dummies book
  • Why Us
    • Fast Reliable Cloud
      • Global Cloud Architecture
      • Cloud Network Status
      • Cloud Network Activity
      • Recursive DNS Services
      • Top Reasons to Trial
      • Getting Started
    • Unmatched Intelligence
      • Cyber Attack Prevention
      • Interactive Intelligence
    • Extensive Integrations
      • IT Security Integrations
      • Hardware Integrations
      • Meraki Integration
      • Cisco SD-WAN
    • Navigation-dropdown-promo-SASE-madness_021721
  • Resources
    • Content Library
      • Top Resources
      • Cybersecurity Webinars
      • Analyst Reports
      • Case Studies
      • Customer Videos
      • Datasheets
      • eBooks
      • Infographics
      • Solution Briefs
    • International Documents
      • Deutsch/German
      • Español/Spanish
      • Français/French
      • Italiano/Italian
      • 日本語/Japanese
    • Cisco Umbrella Blog
      • Latest Posts
      • Security Posts
      • Research Posts
      • Threats Posts
      • Product Posts
      • Spotlight
    • For Customers
      • Support
      • Customer Success Hub
      • Umbrella Deployment Hub
      • Customer Success Webinars
      • What’s New
      • Cisco Umbrella Studio
  • Trends & Threats
    • Market Trends
      • Rise of Remote Workers
      • Secure Internet Gateway (SIG)
      • Secure Access Service Edge (SASE)
    • Security Threats
      • Ransomware
      • Cryptomining Malware Protection
      • Cybersecurity Threat Landscape
    •  
    • Navigation-dropdown-promo-threat-report_020521
  • Partners
    • Channel Partners
      • Partner Program
      • Become a Partner
    • Service Providers
      • Secure Connectivity
      • Managed Security for MSSPs
      • Managed IT for MSPs
    •  
    • Become a partner
  • Free Trial Signup
  • Umbrella Login
  • Cloudlock Login
  • Contact Us
Product

Introducing SecureRank, a large-scale discovery algorithm for predictive detection

By OpenDNS Security Research
Posted on March 28, 2013
Updated on October 15, 2020

Share

Facebook0Tweet0LinkedIn0

dark_graphAt OpenDNS, terabytes of data flow in and out everyday. It takes creativity and solid data science skills to innovate ways to transform an enormous amount of data into security discoveries.
In a series of blogs, we will share algorithmic details of our home-grown discovery algorithms that leverage big data, machine learning and graph theory to make predictive detections.
We start off with SecureRank, which has been presented at a couple security community meet-ups recently. If you haven’t seen it, or prefer video to text, you can watch the SecureRank presentation at this YouTube link.
biparConceptually, a good abstraction of DNS traffic is a bipartite graph. It’s huge, even if you are looking at a small fraction of the Internet. The left set of vertex consists of the client machines (requestors) making DNS requests; the right set of vertex are the hostnames (requestees) that are requested.
So how does a DNS bipartite graph give us an edge in making security discoveries? Consider, for example, the websites Google.com and example.evil.com (a made-up botnet C&C hostname). Imagine that Google.com is much more popular than example.evil.com, as the Google.com vertex appears more densely connected on the graph. The popularity rank can be inferred using page rank-like algorithms. However, popularity alone is a not a good indicator of maliciousness.
What about layering the graph with existing knowledge? There are known bad actors on the Internet, as well as websites we know to be clean. Imagine that we color our graph with different shades of “red” to indicate the bad ones, while “green” for the good ones. We’re likely to see clusters of ‘red’ zones and they are quite separate from “green” zones with few intra links.
We generalize the above rationale and observations as one hypothesis “hostnames requested by known infected clients but never requested by clean clients are most likely to be bad.” Based on this hypothesis, SecureRank ranks the security risks of all hostnames by applying an iterative process similar to the page rank algorithm in the following steps.

The algorithm

Iterative definition

iterativedef_2

Link analysis: This involves marching through global DNS query data and mapping the requestor-requestee pairs as a graph.
Initialization: This gives negative ranks to known blocked domains and assigns positive ranks to known allowed domains.
SecureRank iterations: This concept is illustrated in the simple example below.

simpleex

simpleex2

Convergence and output final ranks: Final ranks are generated when the ranks converge after a number of iterations.   
Implementation: The algorithm is implemented in Java following Hadoop MapReduce framework. Details can be found in the YouTube video mentioned earlier.

Empirical results evaluation

Two metrics were used to evaluate the results: false positive rate and false negative rate. The data sets we used (as the closest thing to gold standard positive set and negative set) are composed of a list of 670,199 known malicious sites and the Quantcast top million sites.
Our hypothesis has stated that domains that receive low SecureRank, in particular, in the negative value range, are more likely to be malicious. At the same time, malicious sites should more likely receive a negative rank, but not necessarily (consider compromised legitimate sites).
The resulting SecureRanks of 83% of the blocked sites are negative.

scatterplot

530 out of the Quantcast top million sites (potential false positive rate = 0.053%) received negative ranks in a particular time window. Further scrutiny of these potential false positives showed that: 1) these sites are on the left end axis of negative values, all in the range of [-0.099,0). 2) Forty five sites were also flagged by Google safe browsing. 3) The majority of these sites are parked domains or spam/scam suspects. None of the sites can be deemed as significant false positives.

SecureRank in action!

SecureRank is integrated into the Umbrella Security Graph. When a query has an alarmingly low SecureRank, an alert bar is shown.

sgraph.sr

Using SecureRank in our back-end classification engine, we’re alerted to 200,000+ likely malicious domains each day. The majority of these sites include spam, scams, botnets or malware. The large-scale discovery technique is used in combination with our other intelligence and predictive algorithms to preventively protect OpenDNS customer from known and unknown security risks.

Previous Post:

Previous Article

Next Post:

Next Article

Follow Us

  • Twitter
  • Facebook
  • LinkedIn
  • YouTube

Footer Sections

What we make

  • Cloud Security Service
  • DNS-Layer Network Security
  • Secure Web Gateway
  • Security Packages

Who we are

  • Global Cloud Architecture
  • Cloud Network Status
  • Cloud Network Activity
  • OpenDNS is now Umbrella
  • Cisco Umbrella Blog

Learn more

  • Webinars
  • Careers
  • Support
  • Cisco Umbrella Live Demo
  • Contact Sales
Umbrella by Cisco
208.67.222.222+208.67.220.220
2620:119:35::35+2620:119:53::53
Sign up for a Free Trial
  • Cisco Online Privacy Statement
  • Terms of Service
  • Sitemap

© 2021 Cisco Umbrella