Careful criminals will surely be able to find a set of software that isn't affected. Australia isn't the US, only a small portion of software companies would have a large local presence here.

I’m sure that will change now.

From small portion to none. And basically Australian software developers are unemployable now.

The problem is that a backdoor might not be so obvious. It can be simply a wrong chosen algorithm key size, and you need to be a cryptographic expert to know that.

That would have to be a systematic weakness... except systematic weakness is probably doublespeak for "whatever the fuck we want to do" anyway.

No reason for them to be getting it.