NETSCOUT: Smarter DDoS security at scale

Encrypted DDoS Attacks Exploit TLS 1.3 Blind Spots, Prompting Smarter Defense Strategies

Threat actors are increasingly leveraging encrypted traffic particularly HTTPS secured by TLS 1.3 to conceal distributed denial-of-service (DDoS) attacks, creating significant challenges for security teams. Since decrypting TLS 1.3 traffic is resource-intensive, many security tools struggle to inspect encrypted sessions effectively, leaving organizations vulnerable to undetected threats.

To counter this, security providers like NETSCOUT employ layered mitigation techniques that filter malicious traffic before decryption. Key methods include:

• Known source blocking: Automatically blocking open internet proxies used to obscure attack origins, powered by threat intelligence feeds like ATLAS.
• TLS handshake analysis: Identifying and blocking non-standard TLS sessions during the pre-encryption phase.
• TCP connection limiting: Restricting sources that exhibit abusive connection behaviors.
• Rate-based protections: Differentiating and blocking traffic volumes exceeding legitimate user patterns.
• Selective decryption: Decrypting only suspicious traffic for deeper inspection, reducing computational overhead.

Full decryption of all traffic is impractical due to performance constraints, prompting a shift toward targeted approaches. NETSCOUT’s Arbor Edge Defense (AED) addresses this by deploying selective decryption at the network edge. The system validates client traffic without decryption where possible, reserving resource-intensive inspection for high-risk sessions. Customizable policies allow organizations to tailor decryption efforts to specific protection groups or threat levels, balancing security and efficiency.

This strategy offers scalable, high-throughput defense against encrypted DDoS attacks while preserving system performance a critical advantage as encrypted traffic volumes continue to rise.

Source: https://www.csoonline.com/article/4117454/smarter-ddos-security-at-scale.html

NETSCOUT TPRM report: https://www.rankiteo.com/company/netscout

"id": "net1769199997",
"linkid": "netscout",
"type": "Cyber Attack",
"date": "1/2026",
"severity": "60",
"impact": "2",
"explanation": "Attack limited on finance or reputation"

{'attack_vector': 'Encrypted HTTPS traffic (TLS 1.3)',
 'description': 'Threat actors are increasingly leveraging encrypted traffic '
                '(HTTPS secured by TLS 1.3) to conceal distributed '
                'denial-of-service (DDoS) attacks, creating significant '
                'challenges for security teams. Since decrypting TLS 1.3 '
                'traffic is resource-intensive, many security tools struggle '
                'to inspect encrypted sessions effectively, leaving '
                'organizations vulnerable to undetected threats. Security '
                'providers like NETSCOUT employ layered mitigation techniques '
                'to filter malicious traffic before decryption.',
 'impact': {'operational_impact': 'Potential service disruption due to '
                                  'undetected DDoS attacks'},
 'lessons_learned': 'Decrypting all TLS 1.3 traffic is impractical due to '
                    'performance constraints; targeted approaches are '
                    'necessary for scalable defense.',
 'post_incident_analysis': {'corrective_actions': 'Adoption of selective '
                                                  'decryption and '
                                                  'pre-decryption filtering '
                                                  'techniques',
                            'root_causes': 'Difficulty in inspecting encrypted '
                                           'TLS 1.3 traffic, leading to '
                                           'undetected DDoS attacks'},
 'recommendations': ['Deploy layered mitigation techniques to filter malicious '
                     'traffic before decryption',
                     'Use selective decryption to balance security and '
                     'performance',
                     'Leverage threat intelligence feeds to block known '
                     'malicious sources',
                     'Implement customizable decryption policies tailored to '
                     'specific protection groups or threat levels'],
 'response': {'containment_measures': ['Known source blocking (automatically '
                                       'blocking open internet proxies using '
                                       'threat intelligence feeds like ATLAS)',
                                       'TLS handshake analysis (identifying '
                                       'and blocking non-standard TLS sessions '
                                       'during pre-encryption phase)',
                                       'TCP connection limiting (restricting '
                                       'sources with abusive connection '
                                       'behaviors)',
                                       'Rate-based protections (blocking '
                                       'traffic volumes exceeding legitimate '
                                       'patterns)',
                                       'Selective decryption (decrypting only '
                                       'suspicious traffic for deeper '
                                       'inspection)'],
              'enhanced_monitoring': 'Selective decryption at the network edge '
                                     '(Arbor Edge Defense - AED)',
              'third_party_assistance': 'NETSCOUT'},
 'title': 'Encrypted DDoS Attacks Exploiting TLS 1.3 Blind Spots',
 'type': 'DDoS',
 'vulnerability_exploited': 'TLS 1.3 blind spots (difficulty in decrypting '
                            'traffic for inspection)'}