Pierluigi Paganini March 04, 2015

Experts at Cisco discovered a new technique dubbed Domain Shadowing consisting in the creation of thousand subdomains used to spread the Angler exploit kit

Cyber criminals have used hundreds of legitimate domain name accounts registered through GoDaddy to run a malicious campaign using the popular Angler exploit kit. Crooks hacked domain name accounts in order to infect visitors with malware, the hackers are using the accounts to create subdomains that direct unaware visitors to websites hosting Angler exploit.

The Angler exploit is one of the most effective exploit kit available in the underground ecosystem, it is continuously integrated by the authors with new exploits and recently it also included the exploits for exploit is one of the most effective exploit kit available in the underground ecosystem, it is continuously integrated by the authors with new exploits and recently it also included the exploits for exploit is one of the most effective exploit kit available in the underground ecosystem, it is continuously integrated by the authors with new exploits and recently it also included the exploits for exploit is one of the most effective exploit kit available in the underground ecosystem, it is continuously integrated by the authors with new exploits and recently it also included the exploits for Adobe Zero-Day vulnerabilities.

The cyber kill chain is simple as efficient, when Internet users view a malicious advertisement is redirected to one of the hacked subdomains hosted by GoDaddy, which delivers the Angler exploit kit or redirects to victims to other malicious website managed by the criminal crew.

It is important to highlight that the owners of the accounts used in the malicious campaign are usually unaware of the illegal activity. Bad actors compromised hundreds of GoDaddy accounts that manage respectively several thousand domain names, then they created thousand of subdomains to serve the Angler exploit, the technique was dubbed by the experts Domain Shadowing.

“With a new technique we’re calling Domain Shadowing, Angler has shown it is working hard to avoid standard detection. Domain shadowing is the process of using users domain registration logins to create subdomains (i.e. says.imperialsocks.com). Angler Exploit Kit has begun utilizing these hijacked domain registrant accounts to serve malicious content. This is an increasingly effective attack vector since most individuals don’t monitor their domain registrant accounts regularly. These accounts are typically compromised through phishing.”  wrote Nick Biasini from Cisco Systems in a blog post.

The domain shadowing technique allows cyber criminals to run malware campaigns alive for longer avoiding take over from security firms and law enforcement, it is more difficult to stop because bad actors can frequently switch to newly generated subdomains.take over from security firms and law enforcement, it is more difficult to stop because bad actors can frequently switch to newly generated subdomains.take over from security firms and law enforcement, it is more difficult to stop because bad actors can frequently switch to newly generated subdomains.take over from security firms and law enforcement, it is more difficult to stop because bad actors can frequently switch to newly generated subdomains.

“Some of the subdomains are only active for a matter of minutes and only are reached a couple of times,” Biasini wrote.

At least 10,000 unique subdomains have been created by cyber criminals on those accounts that have been involved in the Angler campaign. Experts speculate that the GoDaddy domain name accounts are likely compromised by stealing the login credentials through phishing attacks, a consolidate practices that is very effective for an attack on a large scale.

The choice of GoDaddy is not surprising, the company in fact manages nearly a third of the domain names on the Internet, at the time I’m writing GoDaddy representatives still haven’t commented the events.

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Pierluigi Paganini

(Security Affairs –  Angler Exploit, Tor)

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