IPv4 prefix hijacking¶
Attack pattern¶
IPv4 prefix hijacking occurs when an Autonomous System (AS) maliciously or erroneously announces ownership of IP address blocks that belong to another entity. This disrupts internet routing by redirecting traffic through unauthorized paths, enabling interception, surveillance, or denial-of-service attacks.
1. IPv4 Prefix Hijacking [OR]
1.1 Subprefix Hijacking [OR]
1.1.1 Exact Prefix Announcement
1.1.1.1 Announcing another organization's exact IPv4 prefix
1.1.1.2 Using forged origin AS to claim ownership
1.1.1.3 Exploiting lack of Route Origin Authorization (ROA)
1.1.2 More Specific Prefix Announcement
1.1.2.1 Announcing a longer prefix (e.g., /24 instead of /22)
1.1.2.2 Exploiting longest prefix match routing preference
1.1.2.3 Targeted hijacking of specific subnets
1.2 BGP Path Manipulation [OR]
1.2.1 AS Path Prepending Abuse
1.2.1.1 Manipulating path length to influence route selection
1.2.1.2 Creating artificial path preferences
1.2.1.3 BGP community attribute manipulation
1.2.2 Route Leaking
1.2.2.1 Violating export policies to transit providers
1.2.2.2 Accidental or malicious redistribution to peers
1.2.2.3 Multi-hop route propagation abuse
1.3 Attack Objectives [OR]
1.3.1 Traffic Interception
1.3.1.1 Man-in-the-middle attacks for surveillance
1.3.1.2 SSL/TLS certificate manipulation
1.3.1.3 Data exfiltration through rogue paths
1.3.2 Denial of Service
1.3.2.1 Blackholing traffic to specific prefixes
1.3.2.2 Routing loops through inconsistent announcements
1.3.2.3 Path inflation causing latency and packet loss
1.3.3 Financial Motivation
1.3.3.1 Cryptocurrency exchange targeting
1.3.3.2 Ad revenue diversion
1.3.3.3 Competitive advantage through service disruption
1.4 Evasion Techniques [OR]
1.4.1 Time-Based Attacks
1.4.1.1 Short-duration hijacks to avoid detection
1.4.1.2 Pulse hijacking for selective interception
1.4.1.3 Chronologically coordinated attacks
1.4.2 Geographic Distribution
1.4.2.1 Multi-region announcement coordination
1.4.2.2 Exploiting slow global BGP convergence
1.4.2.3 Targeting specific geographic regions
1.4.3 Attribution Obfuscation
1.4.3.1 Using compromised AS resources
1.4.3.2 Route manipulation through multiple hops
1.4.3.3 False flag operations
1.5 Infrastructure Exploitation [OR]
1.5.1 Rogue ASN Registration
1.5.1.1 Obtaining AS numbers through fraudulent means
1.5.1.2 Social engineering against Regional Internet Registries (RIRs)
1.5.1.3 Exploiting temporary ASN allocations
1.5.2 Compromised Router Access
1.5.2.1 Unauthorized access to BGP routers
1.5.2.2 Credential theft for network devices
1.5.2.3 Vendor backdoor exploitation
1.5.3 IXP Manipulation
1.5.3.1 Internet Exchange Point route server exploitation
1.5.3.2 Peering session hijacking
1.5.3.3 BGP session takeover through MD5 weakness
1.6 Advanced Techniques [OR]
1.6.1 AI-Powered Hijacking
1.6.1.1 Machine learning for optimal hijack timing
1.6.1.2 Adaptive attack patterns based on network conditions
1.6.1.3 Predictive routing manipulation
1.6.2 State-Sponsored Operations
1.6.2.1 Nation-level prefix hijacking campaigns
1.6.2.2 Intelligence gathering through traffic interception
1.6.2.3 Geopolitical targeting of specific nations
1.6.3 Zero-Day Exploitation
1.6.3.1 Unknown BGP implementation vulnerabilities
1.6.3.2 Novel route processing flaws
1.6.3.3 Emerging protocol extension abuse
1.7 Persistence Mechanisms [OR]
1.7.1 Long-Term Hijacking
1.7.1.1 Sustained prefix announcements for extended periods
1.7.1.2 Gradual route manipulation to avoid detection
1.7.1.3 Low-volume traffic interception
1.7.2 Recurrence Patterns
1.7.2.1 Periodic re-hijacking of same prefixes
1.7.2.2 Rotating between different target prefixes
1.7.2.3 Seasonal attack patterns based on traffic volumes
1.8 Collateral Damage [OR]
1.8.1 Internet-Wide Impact
1.8.1.1 Global routing table pollution
1.8.1.2 Cascading routing instabilities
1.8.1.3 Multi-organizational service disruption
1.8.2 Economic Consequences
1.8.2.1 Financial service disruption
1.8.2.2 E-commerce revenue loss
1.8.2.3 Recovery cost burden on victims
Why it works¶
Trust-Based Protocol: BGP inherently trusts announcements from peers without cryptographic verification
Limited Validation: Many networks lack Route Origin Authorization (ROA) and RPKI validation
Slow Convergence: Global BGP convergence can take minutes, allowing attacks to persist
Complexity: Internet-scale routing complexity makes manual verification impractical
Economic Factors: Asymmetric incentives where defenders bear costs of protection
Mitigation¶
Resource Public Key Infrastructure (RPKI)¶
Action: Implement cryptographic route origin validation
How:
Create Route Origin Authorizations (ROAs) for your prefixes
Configure routers to validate received routes (ROV)
Maintain current ROAs with correct origin AS numbers
Configuration example (Cisco):
router bgp 65001
bgp rpki server tcp 10.0.0.1 port 323
address-family ipv4
bgp rpki origin-as validation
BGP monitoring and alerting¶
Action: Continuously monitor BGP announcements for unauthorized changes
How:
Subscribe to BGP monitoring services (BGPMon, Cloudflare Radar)
Implement real-time alerting for prefix announcements
Use looking glasses for route verification
Tools: BGPStream, RIPE Stat, and commercial monitoring solutions
Filtering and policy enforcement¶
Action: Implement strict inbound and outbound route filtering
How:
Apply prefix filters based on IRR databases
Use AS path filters to reject improbable paths
Implement max-prefix limits to prevent route flooding
Configuration Example:
ip prefix-list LEGITIMATE-PREFIXES seq 10 permit 192.0.2.0/24
route-map PEER-IN permit 10
match ip address prefix-list LEGITIMATE-PREFIXES
BGP Security extensions¶
Action: Deploy BGPsec for path validation where supported
How:
Implement BGPsec with cryptographic path validation
Phase deployment starting with critical peers
Monitor performance impact and adjust accordingly
Considerations: Requires vendor support and peer participation
Peering agreement enforcement¶
Action: Formalize and enforce peering policies
How:
Establish clear peering contracts with security requirements
Conduct regular configuration audits with peers
Maintain updated PeeringDB records
Best Practice: Participate in Mutually Agreed Norms for Routing Security (MANRS)
Incident response planning¶
Action: Prepare for hijacking incidents with documented procedures
How:
Designate a BGP security response team
Establish communication channels with peers and providers
Document prefix reclamation procedures
Template: Maintain incident response checklists and contact lists
MANRS compliance¶
Action: Join and comply with Mutually Agreed Norms for Routing Security
How:
Implement MANRS requirements for your network type
Undergo compliance auditing and certification
Promote MANRS adoption among peers
Benefits: Improved security posture and industry recognition