Take a look at Gray Hat Hacking: https://www.amazon.com/Hacking-Ethical-Hackers-Handbook-Fourth/dp/0071832386/ref=sr_1_1?ie=UTF8&qid=1512291222&sr=8-1&keywords=Gray+hat+hacking
It has a chapter about Android Malware.
If I remember correctly Packt Publishing also has some books about Android Malware. Another good source is YouTube.
Hope that helps
Our lead instructor is Daniel Regalado author of "Grey Hat Hacking".
A number of different topics will be covered:
Threat Modeling
Security Code Review Overview
Web-Based Vulnerabilities
Buffer Overflow
Integer Overflow
Stack Overflow
Heap Overflow
Our site will be launching soon so stay tuned! Let us know if you have more questions!
Hi, I don't think that being a beginner at 40 would be a problem. If I was in your position, I would do the transition smoothly as I can. That means, keep your job at your current position and learn security during your free time. I am a web developer, and even though I am younger than you, that is what I am doing.
There are great books, like :
"Grey hat hacking, 4th edition", or even the 3rd edition.
"Hacking, The Art of Exploitation"
These two are the ones that I am currently reading and they are very informative books.
You can get a OSCP Certification and there are some online trainings too. One is even free
There are also some subreddits about hacking, like /r/hacking , /r/hackersec where you can find useful resources.
What I suggest you, is go read some books and find some websites about security and hacking. Start learning the same tools as a white hat would use. Start learning new programming languages too.
I won't lie, there are a lot of things to learn. Just surround yourself with these types of informations and play with some tools that you can find online. Read some books and when you are ready, start making the transition between your current job and the one that you want.
Ps : Sorry for my English and I hope this post was useful !
I recommend having a look at both on amazon, you can see the contents, and people give a good overview in the reviews as well:
Gray Hat was the first book. Its more about debuggers.
Not to be confused with Gray Hat Hacking
Blackhat is the 2nd book. More variety.
Violet Python is probably more introductory.
Having said that, I would learn python first of all. python the hardway
Learning python is a bit dry, but covers a lot of the language.
/r/python might better place to ask.