Not able to find Hard coded strings in the mac executable file

Question

I know that there is a string called "Activate your subscription" used in this particular app. But Im not able to find this string from its executable. I tried strings myapp and also searched for same string with Hopper disassembler but it both haven't found location of that string.

So my question what am I missing here and is this some kind of obfuscation used by these apps ?

Image of a screen in this particular mac app where "Activate your subscription" string is used

After Searching for "Activate" string in Hopper

Answer 1

Some binaries hide the string on base64, with basic encryption algorithms rc4 or even with xor just for avoid what you are trying to achieve. Depending on the design of the owner of the binary you can find this types of techniques on them.

For example instead of do this

const char *msg = "Good morning";

You can do

const char *msg = "R29vZCBtb3JtaW5nCg=="; /* base64 of 'Good morning' */

and on every use of msg you just call a base64 decode function and that's how works in a very basic environment. You can use RC4, Xor or any other encryption algorithm for hide the strings, but bear in mind that somebody with experience will find the way to decode the string

printf("My message is %s\n", decode64(msg));