I don't know if you are aware yet, but signal recently had two significant flaws, which are patched in 1.11.0
CVE-2018-10994
CVE-2018-11101
https://ivan.barreraoro.com.ar/signal-desktop-html-tag-injection/
https://ivan.barreraoro.com.ar/signal-desktop-html-tag-injection-variant-2/