DHS issued an emergency directive to federal agencies and it staffs to Audit DNS Records, Change DNS Account Passwords, Add Multi-Factor Authentication and Monitor Certificate Transparency Logs within next 10 business days.
The emergency alert issued after in wake of the ongoing DNS campaigns targeting various domains organizations belonging to various government, telecommunications and internet infrastructure entities.
DNS hijacking is a type of Malicious attack that used to redirect the users to the malicious website when they visit the website via compromised routers or attackers modifying a server’s settings.
These types of attacks begins by gaining access to the acounts that privileaged to make changes with the DNS records.
Once the attackers gains control over the DNS portal of the domains they will change the DNS records such as Address (A), Mail Exchanger (MX), or Name Server (NS) records and points to malicious server address.
A – A record is used to point the domain name such as gbhackers.com to the IP address of it’s hosting server.
MX – Records responsible for Email exchange.
NS – NS records are to identify DNS servers responsible for the domain.
“To address the significant and imminent risks to agency information and information systems presented by this activity, this emergency directive requires the following near-term actions to mitigate risks from undiscovered tampering, enable agencies to prevent illegitimate DNS activity for their domains, and detect unauthorized certificates,” reads the advisory.
Advisory Actions – Within 10 Business Days
- Audit public DNS records on all authoritative and secondary DNS servers and to verify they are pointing to desired locations.
- Update passwords for all the accounts on the system.
- Add multi-factor authentication for all the accounts that are privileaged to make the DNS changes.
- Agencies should monitor the Certificate Transparency (CT) logs for agency domains and to begin monitoring CT log data for certificates issued that they did not request.
The infrastructure agency CISA began to provide regular delivery of newly added certificates to CT logs for agency domains via the Cyber Hygiene service.