What Are Smishing Campaigns? (SMS Phishing Explained)
Smishing—short for SMS phishing—is a cyberattack technique where threat actors send fraudulent text messages to trick users into clicking malicious links, sharing sensitive information, or installing malware. Unlike email phishing, smishing exploits the high trust users place in text messages, as well as the fact that SMS lacks built-in authentication and security controls.
Smishing messages often impersonate trusted brands, apps, service providers, or even worse, security notifications. Attackers use them to harvest login credentials, session cookies, personal data, or MFA tokens.
How Smishing Campaigns Work: Common Tactics
Threat actors use a variety of persuasive techniques to convince victims to take quick action:
1. Brand Impersonation
Attackers spoof messages from banks, delivery companies, SaaS platforms, or even cybersecurity tools.
Example: “Your account is locked. Verify here to restore access.”
2. Malicious Links in SMS
Links lead to phishing pages designed to steal credentials or trigger malware downloads.
3. Exploiting MFA & Session Tokens
Attackers lure users into entering MFA codes or password reset codes, enabling account takeover.
4. Pretexting & Urgency
Messages create a sense of pressure—“Your service will be terminated,” “Payment failed,” “Suspicious activity detected.”
5. Narrow Targeting (Spear-Smishing)
Messages tailored to specific individuals or employees inside a company, often based on OSINT or leaked databases.
Common Examples of Smishing Campaigns
- Fake shipping notifications (“Your package is on hold”)
- Banking verification requests
- Password reset notifications for cloud platforms
- Payroll or HR messages impersonating internal systems
- Fake MFA prompts requesting users to approve a login
Over time, attackers have become more sophisticated, using URL shorteners, stolen brand assets, and lookalike domains to make phishing links look legitimate.
How Smishing Campaigns Facilitate Supply Chain Attacks
While smishing traditionally targets individuals, modern campaigns increasingly enable supply chain attacks. This occurs when threat actors use SMS phishing as the initial access vector to compromise an employee at a trusted company, giving them access to external systems, API keys, or administrative dashboards used by many downstream clients.
Key Ways Smishing Enables Supply Chain Compromise
1. Stealing Credentials From Platform Administrators
An attacker who gains access to an employee’s account in a data analytics, cloud, payment, or marketing platform can misuse that platform to access sensitive customer data.
2. Bypassing Email Defenses
SMS phishing avoids corporate email security controls, making it harder for organizations to detect and block attacks early.
3. Delivering Malware to Key Supply Chain Vendors
Once malware infects a supplier’s employee device, it may capture passwords, VPN access, or SSH keys for corporate systems.
4. Capturing MFA Tokens
If attackers trick employees into providing MFA codes, they can access backend systems shared by multiple clients.
Case Study: Mixpanel-Related Smishing Attack
One of the most recent examples involves Mixpanel, the digital analytics provider. In late 2025, attackers used a smishing campaign to steal credentials from a Mixpanel employee by impersonating internal authentication systems. After gaining unauthorized access, they were able to access analytics data belonging to customers, including OpenAI.
This incident highlights the dangerous ripple effect:
- The initial compromise was caused by SMS phishing targeting Mixpanel staff.
- The impact extended to Mixpanel clients—a classic supply chain breach.
- Downstream organizations had no visibility into the initial intrusion vector.
How to Prevent Smishing Campaigns and Reduce Supply Chain Risk
Organizations need to combine user awareness, technical controls, and supply chain governance to mitigate smishing-enabled attacks.
1. Enforce MFA—but Prefer App-Based or Hardware Keys
Avoid SMS-based MFA whenever possible. Use:
- Authenticator apps (TOTP)
- FIDO2 hardware keys
- Push-based MFA
These reduce the attacker’s ability to steal session codes via smishing.
2. Deploy Mobile Threat Defense (MTD)
Secure mobile devices used by employees—especially those with admin access to supply chain platforms.
3. Conduct Continuous Phishing & Smishing Training
Simulated smishing tests help employees recognize:
- Fake links
- Urgency cues
- Suspicious sender numbers
4. Implement Vendor Access Controls
Limit what external vendors and internal suppliers can access:
- Just-in-time access
- Role-Based Access Control (RBAC)
- OAuth token restrictions
- API key rotation
5. Monitor for Unusual Authentication Patterns
Use behavioral analytics to detect unusual logins, session anomalies, or logins originating shortly after suspicious SMS activity.
6. Validate Supplier Security Posture
Organizations should ensure their vendors implement:
- Strong MFA
- Mobile security
- Social engineering controls
- Incident response processes
Smishing campaigns have evolved from consumer-level scams into sophisticated attack vectors with the power to trigger large-scale supply chain incidents. By using SMS messages to target employees at critical vendors and service providers, attackers can gain access to systems that serve thousands of customers, as demonstrated by the Mixpanel incident.
Preventing smishing-enabled supply chain attacks requires a comprehensive approach: improving mobile security, replacing SMS-based MFA, training employees, and enforcing strong vendor access controls. As the threat landscape continues to evolve, organizations that prioritize secure authentication and supply chain visibility will be far better equipped to block the next wave of smishing-driven intrusions.