SIM Card Attack Vectors
Comprehensive analysis of SIM card security vulnerabilities, including SIM swapping, cloning, OTA exploitation, and cryptographic attacks on mobile subscriber authentication.
Critical SIM Attack Vectors
Social engineering attacks targeting mobile carriers to transfer a victim's phone number to an attacker-controlled SIM card.
Attack Process:
- Gather victim personal information
- Impersonate victim to carrier support
- Request SIM card replacement/transfer
- Intercept SMS-based 2FA codes
Impact:
Account takeover, cryptocurrency theft, banking fraud, identity theft, and complete loss of mobile service.
Creating a duplicate SIM card by extracting cryptographic keys (Ki) and IMSI from the original SIM.
Techniques:
- Physical SIM card extraction
- Side-channel attacks (power analysis)
- Fault injection attacks
- Exploiting weak COMP128v1 algorithm
Mitigation:
Use modern SIM cards with strong cryptography (COMP128v3, Milenage), implement physical security, and monitor for duplicate registrations.
Exploiting vulnerabilities in OTA update mechanisms to remotely compromise SIM cards and execute malicious commands.
Attack Methods:
- SMS-based OTA command injection
- Weak OTA encryption exploitation
- SIM Toolkit (STK) abuse
- Binary SMS manipulation
Consequences:
Remote SIM control, SMS interception, location tracking, premium rate fraud, and data exfiltration.
Exploiting weaknesses in SIM card cryptographic algorithms to extract authentication keys or impersonate subscribers.
Vulnerable Algorithms:
- COMP128v1 (rainbow table attacks)
- Weak A5/1 encryption (GSM)
- A5/2 cipher (intentionally weakened)
- GEA0 (no encryption)
Defense:
Deploy modern SIM cards with Milenage algorithm, enforce strong encryption (A5/3, A5/4), and disable legacy algorithms.
Additional SIM Attack Vectors
Exploiting S@T Browser on SIM cards to remotely track location and intercept information.
Affects legacy SIM cards with vulnerable STK implementations.
Similar to SIMjacker but exploits WIB (Wireless Internet Browser) on SIM cards.
Enables remote surveillance and data theft via SMS.
Scanning for valid ICCID numbers to identify active SIM cards for targeted attacks.
Used in reconnaissance phase of SIM swapping attacks.
Exploiting eSIM remote provisioning to hijack profiles or install malicious configurations.
Emerging threat as eSIM adoption increases.
Malicious STK applications that steal data, send premium SMS, or track location.
Requires physical access or OTA exploitation.
Using fake base stations to force SIM cards to reveal IMSI for tracking and targeting.
Mitigated by IMSI encryption in 5G networks.
SIM Security Best Practices
For Mobile Operators
- •Implement strong customer authentication for SIM changes
- •Deploy modern SIM cards with strong cryptography
- •Monitor for duplicate SIM registrations
- •Secure OTA platforms with strong encryption
- •Disable legacy vulnerable algorithms
For End Users
- •Enable SIM PIN/PUK protection
- •Use app-based 2FA instead of SMS when possible
- •Set up carrier account security (PIN, password)
- •Monitor for unexpected service disruptions
- •Protect personal information from social engineering