Modding IPAs For Premium Access On Apps

Modding IPA Files For Free Paid Access For Apps

iOS binary modification is fundamentally different from Android. No smali here — you're dealing with compiled ARM64 Mach-O binaries, strict code signing, and a locked-down runtime. Here's the full methodology.

IPA Structure

An IPA is just a zip file:

bash

unzip target.ipa -d extracted/
# Structure:
#   Payload/
#     Target.app/
#       Target          ← Mach-O binary (the actual code)
#       Info.plist       ← App metadata
#       Frameworks/      ← Embedded dylibs
#       Assets.car       ← Compiled assets
#       *.mobileprovision ← Provisioning profile (enterprise builds)

Step 1: Static Analysis - Find The Check

Dump class/method information

bash

# Dump all Objective-C classes and methods
nm -U Payload/Target.app/Target | grep -i "premium\|pro\|vip\|subscribe\|purchase\|unlock"

# otool for linked frameworks (look for StoreKit)
otool -L Payload/Target.app/Target

# Strings dump is invaluable
strings Payload/Target.app/Target | grep -iE "premium|sku|purchase|entitlement|isPro|isPremium|trial"

Use Hopper or Ghidra

Hopper Disassembler is the go-to for iOS reverse engineering. Load the binary and it'll give you pseudo-code that's surprisingly readable for Objective-C.

In Hopper, search for:

• Selectors / method names containing premium, pro, vip, purchase, subscription, isUnlocked

• References to SKPaymentQueue, SKProduct, SKReceiptRefreshRequest (StoreKit)

• Strings matching isPremium, isPro, entitlement

Common Objective-C patterns you'll find:

objc

// Pattern 1: Simple bool check
- (BOOL)isPremium {
    return self->_premium;
}

// Pattern 2: Feature gate
- (void)showPremiumContent {
    if ([[UserManager sharedManager] isPremium]) {
        // show content
    } else {
        // show paywall
    }
}

// Pattern 3: Receipt validation
- (BOOL)validateReceipt {
    NSData *receipt = [NSData dataWithContentsOfURL:[[NSBundle mainBundle] appStoreReceiptURL]];
    // ... verify with Apple or own server
}

// Pattern 4: UserDefaults
BOOL isPro = [[NSUserDefaults standardUserDefaults] boolForKey:@"is_pro_user"];

Step 2: Patching Strategies

Strategy A: ARM64 Binary Patch (Direct)

Use Hopper to find the exact instruction, then patch with a hex editor or llvm-objcopy.

Patch isPremium to always return TRUE (1):

ARM64 convention: return value is in x0. A bool-returning method typically ends with:

asm

; Return false (0)
mov    x0, #0x0
ret

; Patch to return true (1):
mov    x0, #0x1
ret

In Hopper, identify the method, then Modify → Assemble Instruction and change mov x0, #0 to mov x0, #1.

For conditionals (CBZ/CBNZ flips):

asm

; Before: cbz w0, show_paywall    ; branch if zero (false) → paywall
; After:  cbnz w0, show_paywall   ; branch if NOT zero (never for false)

Strategy B: Dylib Injection (Theos Tweak)

This is cleaner than binary patching — inject a dynamic library that hooks methods at runtime, similar to Substrate/Xposed on Android.

Install theos:

bash

git clone --recursive https://github.com/theos/theos.git /opt/theos

Create a tweak:

bash

$THEOS/bin/nic.pl
# Choose: iphone/tweak
# Name: PremiumBypass
# Bundle ID: com.target.app

Tweak.xm (Logos syntax):

objc

%hook UserManager

- (BOOL)isPremium {
    return YES;
}

- (BOOL)isSubscribed {
    return YES;
}

%end

// Also hook StoreKit receipt validation
%hook SKReceiptRefreshRequest

- (void)start {
    // Suppress receipt refresh — don't let it invalidate our state
    %orig;
}

%end

// Hook NSUserDefaults to spoof stored values
%hook NSUserDefaults

- (BOOL)boolForKey:(NSString *)key {
    if ([key isEqualToString:@"is_pro_user"] || 
        [key containsString:@"premium"] ||
        [key containsString:@"pro"]) {
        return YES;
    }
    return %orig;
}

%end

Build and install:

bash

make package
# Installs to /Library/MobileSubstrate/DynamicLibraries/ on jailbroken device
make install

Strategy C: Frida (Dynamic Instrumentation)

No build pipeline needed — trace and hook live:

javascript

// premium_bypass.js
if (ObjC.available) {
    // Hook class method
    var UserManager = ObjC.classes.UserManager;
    if (UserManager) {
        var isPremium = UserManager['- isPremium'];
        Interceptor.attach(isPremium.implementation, {
            onLeave: function(retval) {
                console.log("[*] isPremium returning: " + retval);
                retval.replace(ptr(0x1));  // force true
            }
        });
    }

    // Hook NSUserDefaults for backup
    var NSUserDefaults = ObjC.classes.NSUserDefaults;
    var boolForKey = NSUserDefaults['- boolForKey:'];
    Interceptor.attach(boolForKey.implementation, {
        onEnter: function(args) {
            var key = ObjC.Object(args[2]).toString();
            if (key.includes('premium') || key.includes('pro')) {
                console.log("[*] Spoofing boolForKey: " + key);
            }
        },
        onLeave: function(retval) {
            // Force true for premium keys
            // This is crude — refine with onEnter key checking
        }
    });

    // Disable certificate pinning for API interception
    // Hook NSURLSession if needed
}

Run:

bash

frida -U -l premium_bypass.js -f com.target.app --no-pause

objection (built on Frida) has useful shortcuts:

bash

objection -g com.target.app explore
# In objection console:
ios hooking list_classes          # find premium-related classes
ios hooking watch class UserManager  # trace all method calls
ios nsuserdefaults get           # dump all stored preferences

Strategy D: Patch Info.plist + Entitlements

Some apps check premium status through entitlements or plist flags:

bash

# Examine current entitlements
codesign -d --entitlements - Payload/Target.app/Target

# Check Info.plist for premium flags
plutil -p Payload/Target.app/Info.plist | grep -i "premium\|pro\|vip"

If the app reads entitlement-based flags, you can potentially inject your own entitlements and re-sign, though this is rare — most checks are in binary code.

Step 3: Repackaging & Sideloading

This is the hard part on iOS. You need to get the modified app onto the device.

Option A: Jailbroken Device with AppSync Unified

Install AppSync Unified (allows unsigned/fake-signed apps), then:

bash

# Repack
cd extracted
zip -r ../modded.ipa Payload/

# Install directly
scp modded.ipa root@<device_ip>:/var/mobile/Documents/
ssh root@<device_ip> "ideviceinstaller -i /var/mobile/Documents/modded.ipa"

Option B: Sideload with AltStore / Sideloadly (Stock Device)

Re-sign with your developer certificate:

bash

# Extract entitlements from an existing signed app
codesign -d --entitlements entitlements.plist Payload/Target.app/Target

# Re-sign everything
find Payload -name "*.framework" -exec codesign -f -s "iPhone Developer: Your Name" {} \;
codesign -f -s "iPhone Developer: Your Name" --entitlements entitlements.plist Payload/Target.app/Target

# Re-pack
zip -r modded.ipa Payload/

Then use AltStore or Sideloadly to install. The 7-day certificate limitation applies unless you have a paid developer account.

Option C: Enterprise Certificate

If you have an enterprise cert (common in pentest engagements), sign with it and distribute through your MDM or direct install.

Step 4: Dealing With Defenses

Defense	Bypass
Jailbreak detection	Hook stat("/Applications/Cydia.app", ...), NSFileManager fileExistsAtPath: for jailbreak paths, or use Shadow/KernBypass tweaks
Debugger detection	Hook ptrace(PT_DENY_ATTACH, ...) or use dlopen/dlsym to nullify it
Certificate pinning	objection: ios sslpinning disable, or Frida hook URLSession:didReceiveChallenge:completionHandler:
Integrity checks	Hook SecCodeCheckValidity or mach_vm_region checks — these are rare in non-financial apps
Server-side receipt validation	This is the real wall. If the app sends the receipt to Apple's /verifyReceipt endpoint and the server checks the response, client-side patching won't help. You'd need to either intercept/relay with a mitmproxy, or pivot to testing the API directly.
Swift code	Swift uses name mangling — use nm -gU and search for mangled names like $s11com_target4User8isPremiumSbvg. Hopper/Ghidra will demangle these for you. Frida is often easier than binary patching for Swift.

Practical Workflow Script

bash

#!/bin/bash
# iOS IPA pentest workflow
IPA=$1
NAME=$(basename "$IPA" .ipa)

echo "[*] Extracting..."
unzip -qo "$IPA" -d "${NAME}_extracted"

echo "[*] Strings scan for premium indicators..."
BINARY=$(find "${NAME}_extracted/Payload" -name "*.app" -maxdepth 1 | head -1)
APP_NAME=$(basename "$BINARY" .app)
strings "$BINARY/$APP_NAME" | grep -iE "premium|ispro|isvip|issubscribed|sku|trial|entitlement" | sort -u

echo "[*] Checking for StoreKit linkage..."
otool -L "$BINARY/$APP_NAME" | grep -i storekit

echo "[*] Dumping ObjC class methods..."
nm -U "$BINARY/$APP_NAME" | grep -iE "premium|pro|vip|subscribe|purchase|unlock|trial" 

echo "[*] Checking NSUserDefaults keys (if app data exists)..."
plutil -p "${NAME}_extracted/Payload/${APP_NAME}.app/Info.plist" | grep -iE "premium|pro"

echo "[*] Open binary in Hopper: open -a Hopper $BINARY/$APP_NAME"