That's not very clever because the fake Windows alert clearly suggests that the dialog is bogus. Anyway, if you choose to "Remove all" the threats, you will be prompted to download BestMacAntivirus2011.mpkg.zip or something similar. And if you run it, you will end up with the fake MAC Defender anti-virus software.
After installation, MAC Defender world's leading security solution splash screen shows up.
Then the main scanner windows loads up and pretends to scan your Mac for malware and then reports non-existent viruses to make you think that you are infected.
It displays fake security alerts every few minutes. The rogue program states that you are infected with spyware, rootkits, dialers, adware and other malicious software. It may even load porn and viagra websites to imply that your computer is compromised. It goes without a saying that MAC Defender is a scam because it doesn't do anything. It shows the fake security alerts and asks you to obtain a full version of the application in order to remove the non-existent threats. Do not purchase this rogue AV software because there really is no guarantee that your credit card details aren't going to be sold to other third parties. Besides, it won't protect your computer anyway. To remove MACDefender from your computer, please follow the steps in the removal guide below.
MACDefender is configured to start automatically when your computer starts because it adds itself to the user's Login Items. There is no Dock icon linked to this rogue AV. You need to open Activity Monitor and close the program manually. Then you can open Applications folder and remove MACDefender.app manually. Or you can download legitimate anti-virus software and run a full system scan. If you need more help with this rogue program, you can always leave a comment. Good luck and be safe online!
It should not to be confused with the software developer of the same name macdefender.org. The owner of that website said that he has nothing to do with this phony anti-virus software which came out a few days ago.
MACDefender removal instructions:
1. Open Applications → Utilities → Activity Monitor and terminate processes linked to MACDefender.
2. Delete MACDefender from the Applications folder.
3. Check System Preferences → Accounts → Login Items for MAC Defender entry.
4. Run a Spotlight search for "MACDefender" to check for any associated files and remomove them if exist.
5. Download ESET Cybersecurity for Mac (free trial, fully functional) or Sophos Anti-Virus for Mac (free) and run a full system scan.
Associated MACDefender files: