Opera is also being affected - it is with some adguard IP address.
See:
http://www.herdprotect.com/adguardadblockeradguard.com.xpi-04c34ab118027ecf0fb076a083dac03d2c7c90bb.aspx

The threat: http://www.microsoft.com/security/portal/threat/encyclopedia/entry.aspx?Name=Trojan:HTML/Redirector.BB

pol