I've used this JailBreak detection in one of my project.
With this, you can prevent the possibility.
if ([DTTJailbreakDetection isJailbroken]) {
// your custom activity and business logic here
}
Also, In precise you can use the below snippet:
BOOL isJailbroken()
{
#if !(TARGET_IPHONE_SIMULATOR)
if ([[NSFileManager defaultManager] fileExistsAtPath:@"/Applications/Cydia.app"] ||
[[NSFileManager defaultManager] fileExistsAtPath:@"/Library/MobileSubstrate/MobileSubstrate.dylib"] ||
[[NSFileManager defaultManager] fileExistsAtPath:@"/bin/bash"] ||
[[NSFileManager defaultManager] fileExistsAtPath:@"/usr/sbin/sshd"] ||
[[NSFileManager defaultManager] fileExistsAtPath:@"/etc/apt"] ||
[[NSFileManager defaultManager] fileExistsAtPath:@"/private/var/lib/apt/"] ||
[[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:@"cydia://package/com.example.package"]]) {
return YES;
}
FILE *f = NULL ;
if ((f = fopen("/bin/bash", "r")) ||
(f = fopen("/Applications/Cydia.app", "r")) ||
(f = fopen("/Library/MobileSubstrate/MobileSubstrate.dylib", "r")) ||
(f = fopen("/usr/sbin/sshd", "r")) ||
(f = fopen("/etc/apt", "r"))) {
fclose(f);
return YES;
}
fclose(f);
NSError *error;
NSString *stringToBeWritten = @"This is a test.";
[stringToBeWritten writeToFile:@"/private/jailbreak.txt" atomically:YES encoding:NSUTF8StringEncoding error:&error];
[[NSFileManager defaultManager] removeItemAtPath:@"/private/jailbreak.txt" error:nil];
if(error == nil)
{
return YES;
}
#endif
return NO;
}
Also , Obfuscation in iOS - objective C you can use this open source-library and for Methods & Classes.