Ironically, the people looking for a free license key are usually trying to clean a virus they got from downloading "free" software earlier. By searching for cracks, you are walking into the exact same trap.
Instead of searching for a "free key," look for a coupon. The official GridinSoft store often runs 50-70% discounts for holidays or new users. A 1-year license for 1 PC often costs less than a pizza.
Instead of risking your digital security with unauthorized keys, you can use these official methods to try or purchase the software: