I tried to download the Cryengine SDK and i got a virus that was picked up and my antivirus sofwatre immediately terminated it. Could anyone tell me what happened.

Basically if you havent already found out,
the way the programs are encrypted are a kinda the same as a virus so you Anti-Virus picks it up as being a virus. BTW is your anti-virus AVG as thats mine and exactly same thing happened. if you want to solve this problem you neeed to turn your anti-virus off or if its AVG thenn AVG's activesheild or the equivalent in another antivirus.
This worked for me,hope it works for you.