Researchers shut down 15,000 subdomains pitching snake oil products and other scams. The takedowns are linked to affiliate marketing campaigns peddling everything from weight-loss solutions and brain-enhancement pills. Those behind the spam campaigns used a technique called domain-shadowing, and they were able to compromise thousands of servers and abuse hundreds of domains and website admin account credentials. The redirections were leveraging compromised servers, researchers discovered, using a simple substitution code and a Caesar cipher.
Source: https://threatpost.com/godaddy-shutters-subdomains-snake-oil/144147/