Tesseract is mostly used to recognize text from images.
From what I understand you want to protect yourself from phishing.
A very good way to do that is to familiarize yourself with Levenshtein distance algorithm.
It's very simple - it calculates how many changes you need to make to a string to get to the desired string.
For example if you have paiipal and compare it to paypal it will give you a distance of 3 - remove 2 letters and add 1.
Why am I suggesting this - because your problem has already been solved in a slightly different situation - corporate world.
Sometimes a bad employee in a company would try to switch the company name on a document with the same name but 2 letters are swapped for example,
small alterations like this are hard to notice for a human, like you pointed out, but for a machine is very easy.
I hope this helps, if not, maybe I did not fully understand your intentions and you would have to clarify why you need to use Tesseract so I can further help you.