This is the warning I got downloading 1.6 just now.
URL: https://secure.expressionengine.com/download.php?ACT=download
C:\Users\*****\Desktop\ExpressionEngine1.6.0.zip
Corrupted archive - wrong original size
I am pretty sure this is a false positive, but since it doesn’t tell me the details I can’t verify it.
I downloaded the file, unzipped it, scanned it and found no problems.
Incase its a question, avg is an antivirus program found here: