From the web & browser security thread:
TFL supports TLS 1.0 through 1.2. In order to avoid constant mixed-content warnings, though, you'll have to go to UserCP, pick "Edit Options" on the left, and uncheck "Show Images". This will turn embedded images into links, rather than showing the image inline.
By changing that setting, you can avoid any possibility of getting false malware positives due to inlined external images. If you turn off "show images" and you still get malware warnings, you 99% probably have malware.