Hello, dear friends.
me and my friends are a little lucky in finding system vulnerabilities, we helped many software companies and game companies, I don't remember the number;)
We have been able to use avg internet security full version legally free of charge for quite some time maybe 1 year,
we have no idea if you did it on purpose ?,however, when you enter credit card information on your campaign after you enter and exit the purchase, you give 2 months free full version.system tries to get credit card payment after two months free full version,So far everything is normal 
however, because we enter virtual card information, the system cannot receive payment from us, when we are completely out of time, we re-enter and exit the purchase section and give us a free trial campaign again,and by entering virtual card information again, we are able to continue using the full version again, repeating it every two months, making the use of the full version completely sustainable.
you don't need any additional software to do this completely sustainable through a campaign you offer,just a legal virtual card!!!
me and my friends are happy to inform you about this and wish you continued success