If you have ever used G-Archiver to archive/backup your Gmail data. Change your Google account password immediately before it is too late. The software was found sending user's login ID and passwords back to the author secretly without user's permission.
Read this post for details. I tried to verify the claim by downloading one version here (the official one is down). My anti-virus software prompted me for an Infostealer.Geemarc virus when I try to extract the zip file, and you may be interested in the advisory for the virus updated on 10th March 2008. Also checked out the scan result of the installer from VirusTotal. Seems that it's a quite well-know fact now and doesn't need any further verification anymore.
So, you can see how malicious programmers could hurt you now. Only trust those trustworthy please!