Telecommunications Incident Response Guide
Comprehensive procedures for detecting, containing, and recovering from telecommunications security incidents including SS7 attacks, GTP breaches, and SIM swap fraud.
Time is critical during security incidents. Follow established procedures, maintain communication, and document all actions. Contact law enforcement and regulatory authorities as required.
Incident Response Framework
NIST-based incident response lifecycle for telecommunications
Preparation
- •Team formation
- •Tool deployment
- •Playbook development
- •Training exercises
Detection & Analysis
- •Incident identification
- •Scope assessment
- •Severity classification
- •Team activation
Containment, Eradication & Recovery
- •Threat isolation
- •Evidence preservation
- •System restoration
- •Monitoring
Incident Severity Classification
Critical (P1)
Criteria: Active SS7/GTP attack, mass subscriber impact, data breach
Response: Immediate escalation, 24/7 response, executive notification
High (P2)
Criteria: Targeted attack, limited subscriber impact, service degradation
Response: 4-hour response time, senior management notification
Medium (P3)
Criteria: Suspicious activity, potential threat, isolated incident
Response: 8-hour response time, team lead notification
Low (P4)
Criteria: Policy violation, minor security event, false positive
Response: Next business day, standard documentation
Incident Response Preparation
Building capability before incidents occur
Team Structure
- ✓Incident Response Manager: Overall coordination and decision-making
- ✓Security Analysts: Threat detection and analysis
- ✓Network Engineers: System access and technical support
- ✓Forensics Specialists: Evidence collection and analysis
- ✓Communications Lead: Stakeholder and media relations
- ✓Legal Counsel: Regulatory compliance and legal guidance
Tools and Technology
- ✓SIEM platform with telecom-specific correlation rules
- ✓Network packet capture and analysis tools
- ✓SS7/SIGTRAN/Diameter monitoring systems
- ✓Forensic workstations and evidence storage
- ✓Secure communication channels (encrypted chat, conference bridge)
- ✓Incident tracking and documentation platform
Documentation
- ✓Incident response plan and procedures
- ✓Attack-specific playbooks (SS7, GTP, SIM swap)
- ✓Contact lists (internal team, vendors, authorities)
- ✓Network diagrams and asset inventory
- ✓Evidence handling procedures
- ✓Communication templates and escalation matrix
Detection and Analysis
Identifying and assessing security incidents
Detection Sources
Automated Detection:
- • IDS/IPS alerts
- • SIEM correlation rules
- • Anomaly detection systems
- • Signaling firewall blocks
Manual Detection:
- • Subscriber complaints
- • Fraud team reports
- • External notifications
- • Threat hunting activities
Initial Analysis Checklist
1Verify the incident is genuine (not a false positive)
2Identify affected systems, networks, and subscribers
3Determine attack vector and entry point
4Assess current impact and potential escalation
5Classify incident severity (P1-P4)
6Activate appropriate response team members
7Begin incident documentation and timeline
8Preserve initial evidence and logs
Containment and Eradication
Stopping the attack and removing threat actor access
Short-term Containment
- ✓Block malicious point codes, GTIs, or IP addresses
- ✓Isolate affected network segments
- ✓Disable compromised accounts
- ✓Increase monitoring and logging
- ✓Preserve forensic evidence
Long-term Containment
- ✓Deploy additional security controls
- ✓Rebuild compromised systems from clean backups
- ✓Implement compensating controls
- ✓Conduct thorough system audits
- ✓Maintain heightened monitoring
Eradication
- ✓Remove malware and backdoors
- ✓Patch exploited vulnerabilities
- ✓Reset compromised credentials
- ✓Update firewall and IDS rules
- ✓Verify threat actor removal
Recovery and Post-Incident Activities
Restoring operations and learning from incidents
Recovery Procedures
- • Restore systems from verified clean backups
- • Gradually return services to normal operation
- • Monitor for signs of recurrence or persistence
- • Validate security controls are functioning
- • Communicate restoration status to stakeholders
- • Document recovery timeline and issues
Post-Incident Review
Incident Timeline
- • When did the incident begin?
- • How was it detected?
- • What was the response timeline?
Root Cause Analysis
- • What vulnerability was exploited?
- • How did the attacker gain access?
- • What controls failed?
Impact Assessment
- • How many subscribers were affected?
- • What data was compromised?
- • What was the financial impact?
Lessons Learned
- • What worked well in the response?
- • What could be improved?
- • What preventive measures are needed?
Incident-Specific Playbooks
Quick reference guides for common telecommunications incidents
SS7 Location Tracking Attack
Indicators:
- • Unusual PSI/SRI requests
- • Foreign point code queries
- • Subscriber complaints
Response Steps:
- 1. Identify source point code
- 2. Block malicious GT/PC at STP
- 3. Review roaming agreements
- 4. Notify affected subscribers
SIM Swap Fraud
Indicators:
- • Unauthorized SIM changes
- • Account takeover reports
- • Unusual port-out requests
Response Steps:
- 1. Freeze affected accounts
- 2. Reverse unauthorized SIM swaps
- 3. Contact law enforcement
- 4. Review authentication procedures
GTP Tunnel Hijacking
Indicators:
- • Duplicate TEID usage
- • Unexpected GTP traffic
- • Data routing anomalies
Response Steps:
- 1. Identify rogue GGSN/PGW
- 2. Block malicious IP ranges
- 3. Audit GTP firewall rules
- 4. Review interconnect security
Related Resources
Additional telecommunications security resources