pcxFirefox’s patches are hosted in https://github.com/xunxun1982/pcxfirefox/tree/master/patches/release/firefox , tmemutil module source code is hosted in https://bitbucket.org/xunxun/tmemutil-3rd , so if you feel some doubt for the virus, you can check the code above or build it yourself.
I did a post about this sometime back , and now another post to spread awareness of this ongoing scam. The best practice is to never click links in Emails. Whenever you join a social page or group, bookmark that link, and use it instead. Also remember to never give out personal information if they ask through an Email, and keep your firewall and antivirus software updated.