DNS Hijacking has been around for a while. Initially it began as a way for the bad guys to take you to a fake website so that your credit card info could be stolen, or so that you could be loaded with malware. But that’s changed to the point where you might never know that your internet sessions have been hijacked, and that your credentials have been stolen, despite using safeguards such as SSL. In some cases, even VPN sessions may not be enough to protect you.
What’s happening is that the threat actors are manipulating your organization’s DNS records so that your users will find themselves going to a site operated by the malicious parties, and from there, will be directed to the site they originally intended to visit. As the traffic passes through the bogus site, the threat actors harvest your user credentials from the traffic before passing it along.
Because many organizations use SSL to protect their traffic, the bad guys will also steal your SSL certificates so that their site can masquerade as your legitimate destination. There have been two recent campaigns carrying out this sort of attack. The first, found in late 2018 was called DNSpionage, and resulted in warnings from the Department of Homeland Security.
The more recent version, called Sea Turtle, is able to modify DNS records by attacking domain registrars. According to a report by Cisco Talos, the attacks happen at all levels of the domain registration system. The initial entry may be gained through phishing attacks.
Server and the Man-in-the-Middle Attack
Initially the Sea Turtle attacks were against government entities, primarily in the Middle East and North Africa. The attackers gain entry into the domain registrar and then modify the DNS records to send traffic to the server operated by the threat actors. That server then becomes a man-in-the-middle attack when it sends the traffic along to the ultimate destination.
Once established, the MitM server can also emulate a VPN endpoint using Cisco’s Adaptive Security Appliance products by abusing the trust relationship with ASA’s SSL certificates. The campaign also facilitated its attack by exploiting vulnerabilities in some Cisco appliances.
So if the attacks are primarily targeting national security organizations in the Middle East and North Africa, should you worry? The answer is yes. The Researchers at Cisco Talos explain:
“We are concerned that the success of this operation will lead to actors more broadly attacking the global DNS system,” they write in their blog. “DNS is a foundational technology supporting the internet. Manipulating that system has the potential to undermine the trust users have on the internet. That trust and stability of the DNS system as a whole drives the global economy.”
DNS Attacks Now Coming from Newer Sources
There’s no reason to believe that these attacks will remain state-sponsored, and in fact there are already indications that they have begun to move beyond that. And there’s no reason to believe that they will remain in the Middle East and North Africa, and as has been the case with other state-sponsored attacks, every reason to believe they will spread.
The next question is what you should do to prevent this type of attack from happening to you. For the most part, the answer is to practice good security habits, and to take a few specific steps as recommended by Talos and DHS.
- Use DNS Security Extensions (DNSSEC) at your registrar. Yes, it costs extra, but not using it is stupid.
- Use a registry lock service, which require an out-of-band message before changes can occur.
- Use multi-factor authentication, such as DUO which is recommended by Cisco Talos.
- If you think you were targeted, Talos suggests institute a network-wide password reset.
- CISA recommends an audit of public DNS records to verify that they are resolving as intended.
- CISA also recommends searching for any encryption certificates related to suspect domains and to revoke any fraudulently requested certificates.
Meanwhile, update your training on phishing attacks, since nearly all of these attacks include phishing somewhere in the mix.
I should also add that if this sort of attack is being carried out by a skilled attacker, it’s nearly impossible to know it’s happened. This means that the best you can do is prevention.