In recent update of Google Chrome internet browser (in stable channel), there is a new security/privacy option:
http://chrome.blogspot.com/2012/02/faster-browsing-safer-downloading.html
In addition to checking a list of known bad files, Chrome also does checks on executable files (like ".exe" and ".msi" files). If the executable doesn't match a whitelist, Chrome checks with Google for more information, such as whether the website you're accessing hosts a high number of malicious downloads.
According to more detail link
If a file isn’t from a known source, Chrome sends the URL and IP of the host and other meta data, such as the file’s hash and binary size, to Google.
What if I want google not to know which executable files are downloaded by me and from?
How can I disable sending to google URLs and hashes of .exe and .msi downloaded?