The listed homepage for VideoDownloader 1.1.1 is http://videodownloader.net/ which redirects you to http://javimoya.com/blog/youtube_en.php. As soon as this page loads it tries to infect your computer with a variety of malware. Sometimes it pops up a phishing dialog claiming that your computer is infected and then offering to disinfect it for you. I didn't test to see exactly how many varieties of malware it tried to put on my PC. Please remove all links to http://videodownloader.net/*
Additionally someone should audit the code for this extension to see if it does anything dodgy.
It is likely they have an XSS exploit on their site. I removed the URL.
Also contacted the author about the URL removal.
No reply from author, but the link is fixed now and doesn't make phishing filters freak out. Reopen if you see anything fishy, but I think we're good here.
Verified WFM too.