Malware Domains List (MDL) is a popular website among security professionals and others interested in IT security. Now a rogue antivirus promoter seems to have latched onto its popularity by setting up a website on a URL very close to MDL's domain.
Visitors expecting to see this:
May instead end up seeing the following:
Note the difference in the URL between the legitimate website and the fake.
Despite a few grammatical errors, the warning does a decent job of looking like a legitimate notice from Firefox. Compare it to the (legit) one below:
Note the "Get security software" button on the malicious website's "warning" message. If clicked, the user is directed to a website promoting a rogue antivirus solution.