An unknown attacker modified the name servers assigned to 751 domains.
That move led to visitors being redirected to a site hosting the Rig Exploit Kit and delivering the Neutrino Bot.
The attack started last Friday, and was made possible through use of compromised login credentials of one of French domain registrar and web host Gandi’s technical partners (through whom they manage domain names in 34 geographic TLDs, including .ASIA, .CH, .ES, .RU, and .JP), Gandi officials said in a post.
Once the attacker gained unauthorized access to the technical partner’s web portal, he or she made the changes to the assigned name servers, and the attack was on.
Swiss information security company SCRT was one of the first to notice the incident.
“Last Friday at around 14:05 we noticed that our website (www.scrt.ch) along with some other services we use internally were no longer accessible. We immediately tried to figure out why that was and quickly noticed that our DNS requests were not returning the correct IP addresses,” they said in a blog post.
They found out the DNS configuration at the registrar and in their name servers was not modified and everything should be normal. But it was not. They then contacted SWITCH, who’s responsible for registering domain names ending in .CH and .LI, and discovered they received a change request from Gandi.
“Following further discussion with them, they found that similar changes had been requested for 94 .CH and .LI domain names,” SCRT officials said.
Gandi changed the compromised login credentials mere minutes after having been notified of the suspicious modifications, and started to undo the damage, while also starting a parallel investigation to see whether their infrastructure has been compromised.
Gandi’s investigation found they haven’t been breached, but the technical partner’s infrastructure has been breached.
“These credentials were likewise not obtained by a breach of our systems and we strongly suspect they were obtained from an insecure connection to our technical partner’s web portal (the web platform in question allows access via http),” they said.
“The first [name server] modification occurred at 8:04 UTC and the last was performed at 9:44 UTC. The last name server update was undone at 13:50 UTC. Taking into account the delay in name server provisioning at the individual registries in question and the TTLs of the relevant DNS zones, the unauthorized changes were in place at the most for 8 to 11 hours,” they said.
“By 16:15 UTC, all unauthorized updates we had reversed at each of the registries and we only needed to wait for propagation delay (up to three hours later) to be completely sure that the modifications had been successfully reversed.”
SCRT will make changes to lessen the impact of such an attack in the future. In addition, they talked to SWITCH on how detection of this type of massive changes can be improved.