We know about the vulnerability, not the payload delivered through it. There could be thousands of them with wildly varying characteristics. There could be none.

Some of them could be rootkits, and have patched filesystem and process explorers to hide themselves. Some could be called virus.exe.

But no, you will never know that you haven't been compromised. In the coming weeks, we may learn about some of the specific malware that spreads this way, and you may be able to test your phone for it, but finding nothing does not mean you haven't been owned by something more exotic.