On two MacBooks (OSX 10.7.5) I get plenty of messages »Vulnerability Blocked« with identification message of »Web Attack: Plugin Detect Research« - please refer to the attached screen shot. On clicking »Learn more« I find the signature »System Infected: Trojan.Ransomlock.K 5«. However, this signature is not listed in the Vulnerability Protection Signature List of my Norton Antivirus Software (Version 12.7)! Running Norton System & File Scan does not find anything on both computers. I suppose these messages are false and there is no danger to my computers (after all this Trojan seems to be active on Windows platforms only).
One of the websites reliably generating the message is http://kurier.at/ (a major Austrian newspaper)
Please check!
Note: I mentioned this problem before in a posting to »Firewall says Trojan, Antivirus says none, help please«