How to Detect VPN using Swift

Struggling to protect your app from hidden network traffic? Here’s how to fight back.

VPNs are widely used for privacy, but they can also be exploited to bypass geo-restrictions, manipulate in-app content, or hide fraudulent activity. Detecting VPN usage in your iOS app is challenging, but there are solution which make it practical and reliable.

What is VPN?

A VPN (Virtual Private Network) encrypts traffic and routes it through remote servers. While this protects privacy, it can also help attackers:

• Bypass geo-restrictions (e.g., accessing services from unsupported countries)

• Hide malicious activity like bot traffic or credential stuffing

• Exfiltrate sensitive data undetected

Attackers often use common VPN apps (NordVPN, ExpressVPN, ProtonVPN) or system-level tunnels to disguise their actions. From a security perspective, detecting VPN usage is like knowing if a user is “wearing a mask”.

Usage of VPN does not automatically impose threat.

How to Detect VPN Usage?

Detecting VPNs isn’t trivial—many providers change IPs, use stealth protocols, or blend with normal traffic. DIY solutions (like hardcoding VPN IP ranges) are unreliable and outdated quickly.

Instead, use expert SDKs that:

• Actively monitor for VPN interfaces and tunnels

• Stay updated against new evasion techniques

• Provide callbacks so your app can respond instantly

Popular Libraries for VPN Detection

freeRASP (by Talsec)

The most robust, developer-friendly and free choice for iOS.

• Actively maintained

• Comes with 14 extra detections like app integrity, runtime manipulation (hooking with Frida), emulators, debugging, screenshots, etc.

• Trusted by 6000+ apps worldwide

Integration Example:

import TalsecRuntime

let config = TalsecConfig(
    appBundleIds: ["YOUR_APP_BUNDLE_ID"], 
    appTeamId: "YOUR TEAM ID", 
    watcherMailAddress: "WATCHER EMAIL ADDRESS", 
    isProd: true
)

extension SecurityThreatCenter: SecurityThreatHandler {
    public func threatDetected(_ securityThreat: TalsecRuntime.SecurityThreat) {
        print("Found incident: \(securityThreat.rawValue)")
    }
}

public enum SecurityThreat: String, Codable, CaseIterable, Equatable {
    // ... other cases ...
    case systemVPN
    // VPN detected
}

Malwarelytics for Apple

• Aside from VPN detection, it also contains additional security checks

• Enterprise grade of checks

• Might be expensive for small apps

Integration Example:

class RaspDelegate: AppProtectionRaspDelegate {
    func vpnChanged(active: Bool) {
        // handle VPN detection
    }
}

Comparison Table

Feature	freeRASP	Malwarelytics
Works Offline	Yes	Yes
Easy Integration	Yes	Yes
Broader Security Coverage	Yes	Yes
Free	Yes	No

Key Takeaway

VPN usage can bypass app restrictions and pose security risks, but detection doesn’t have to be DIY or error-prone. Tools like freeRASP provide reliable, continuously updated detection, letting you respond proactively to potential threats.

👉 If you want VPN detection plus root, Frida, emulator, and tampering protection in one free package, start with freeRASP by Talsec.