A joint advisory issued on April 3 by government officials in the US, Australia, Canada, and New Zealand warns of a significant threat to national security due to the increasing use of the “fast flux” technique by nation-state actors and cybercriminals. Fast flux is a DNS evasion technique that allows threat actors to change domain name system records, evade detection, and compromise enterprise networks.
Experts say the recent surge in fast flux usage highlights a shift in how threat actors leverage this technique, making it more resilient and challenging to disrupt. “Fast flux isn’t just about hiding malicious infrastructure anymore – it’s about creating a command-and-control system that’s almost bulletproof,” said Casey Ellis, founder of Bugcrowd.
The advisory specifically mentions ransomware gangs and Russian APT groups, but other nation-state entities and organized cybercriminal groups have also adopted fast flux to bolster their operations. The technique has been used by various adversaries in the past, including the Storm botnet and the Gamaredon Group.
“This advisory is not routine,” said Callie Guenther, senior manager of cyber threat research at Critical Start. “It identifies a persistent tactic now embedded in adversary operations and warns of a capability gap among defensive services.” Organizations should validate their DNS monitoring capabilities and engage with service providers to detect and mitigate fast flux attacks.
The technique presents detection challenges due to its dynamic nature, but it provides operational cover for threat actors. “Fast flux impedes attribution, disrupts forensic investigations, and supports the longevity of campaigns,” said Guenther.
John DiLullo, CEO of Deepwatch, believes the advisory will hit many companies like a double espresso. “Any enterprise relying on IP reputation as a credible means of securing their infrastructure or proprietary data is a soft target for this type of exploit.” Correlative detection techniques can defeat these intrusions, but many companies’ infrastructures need to be improved.
The joint advisory serves as a wake-up call for organizations to prioritize fast flux detection and mitigation in both defensive strategy and threat intelligence analysis.
Source: https://www.scworld.com/news/nsa-fast-flux-dns-evasion-technique-now-a-national-security-threat