Obviously they are fake.
the are very real :) at least viruses you'll get from downloading something they suggest. they generate random string that have 0.0001% to work as valid key. but then if it happens to be a key (or wallet code) that someone bought they can claim to steam support that someone alrealy stole their code. and you have 100% chance to have issues with steam.
everything is very real :)
Stay away from the Internet's version of AIDS. ALL Free Key/Free Code/No Survey/Instant Verification websites are fake.
If you do not believe the Nigerian Prince, and his free $1,000,000, why would you believe such sites?
Stay cynical, and be wary of sites which offer you free items for minimal effort.
A free key site is something totally different than a so-called generator
Generators are always 100% without any doubt SCAM that rip you off one way or the other
Best case scenario: you'll get stuck in endless loops of doing survey that earning money for the owner of "the generator"
More likely scenario: basically everything oxana told you, or worse
@Kabash wait wut??? You're saying i won't get my $1.000.000 from my dear Abegunde?? 
in 3 steps
Choose the game that interests you and play itfor free.
Every game has some quests for which you will receive Soul Gems.
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You know that on Gamehag you can get real rewards for free, right? Join us, complete walkthrough and get your chest!
Can someone tell me because the internet is full of them and I dont know if they are fake