Be careful when you download new software. Download from the actual creator of the software as much as possible. Avoid getting software from bittorrents. If you do, at least look at the comments of the bittorrent you plan on downloading.
Search engines such as google are great for finding software, but not always the safest. Its best to get software directly from the organization that created not random sites.
For example, at one time “Joydownload. com” was among the top results for the “Yahoo Messenger” and other apps. But this site may have trojans in it.
Joydownload is a known malware distributions site:
Joydownload scan From VirusTotal: