FBI, CISA warns of new Fast Flux DNS evasion being used by cyber gangs

• CISA, FBI, and partners warn of 'fast flux' attacks
• The technique involves attackers rapidly changing the IP addresses of their malicious domains
• To tackle the threat, organizations should go for a multi-layered approach

The US Cybersecurity and Infrastructure Agency (CISA) has warned government agencies, internet service providers (ISP), and other organizations, about so-called “fast flux attacks” which, it says, are becoming a growing problem in cyberspace.

Fast flux attacks are a technique where attackers rapidly change the IP addresses associated with a malicious domain using a botnet, making it difficult to track and take down.

This method helps hide phishing sites, malware distribution networks, and command-and-control servers by leveraging a constantly shifting pool of compromised hosts.

Monitor your credit score with TransUnion starting at $29.95/month

TransUnion is a credit monitoring service that helps you stay on top of your financial health. With real-time alerts, credit score tracking, and identity theft protection, it ensures you never miss important changes. You'll benefit from a customizable online interface with clear insights into your credit profile. Businesses also benefit from TransUnion’s advanced risk assessment tools.

Preferred partner (What does this mean?)

View Deal

Mitigating the threat

CISA published a new security advisory to warn about the threat, together with the FBI, NSA, Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC), Canadian Centre for Cyber Security (CCCS), and New Zealand National Cyber Security Centre (NCSC-NZ).

“Many networks have a gap in their defenses for detecting and blocking a malicious technique known as “fast flux,” the advisory says.

“This advisory is meant to encourage service providers, especially Protective DNS (PDNS) providers, to help mitigate this threat by taking proactive steps to develop accurate, reliable, and timely fast flux detection analytics and blocking capabilities for their customers.”

CISA also provided guidance on how to detect and mitigate fast flux attacks, which includes adopting a multi-layered approach through DNS analysis, network monitoring, and threat intelligence.

It further stated agencies should work together on building and deploying scalable solutions that will “close the ongoing gap” in network defenses.

Finally, the agencies stressed that some legitimate activity, such as common content delivery network (CDN) behaviors, “may look like” malicious fast flux activity.

“Protective DNS services, service providers, and network defenders should make reasonable efforts, such as allowlisting expected CDN services, to avoid blocking or impeding legitimate content,” the advisory concludes.

Via The Register

You might also like

• Security experts take down spam network hitting millions of iOS devices
• We've rounded up the best password managers
• Take a look at our guide to the best authenticator app