What is Probe hack Oposed or extended test?
As it tuned out, it is a little bit of both.
You could say that it is an unprecedented and unique Opposed Cracking + Logic vs Willpower + Firewall or Firewall x 2 (0, 1 Minute) Extended Test
Where you need to score a tie or better on the opposed test to be successful with the whole extended test (the net hit threshold for the Extended test to be successful seem to be 0), but if your opposed test is successful then you can also choose to continue taking more opposed tests - if you like (in some cases this will be worth it, in other cases you might want to stop after your first successful test and it seem as if you in some cases want to reset and then fish for a really good roll on your first minute of probing).
If you do, then each opposed test take 1 minute and you keep the sum of all net hits from all your opposed tests (the sum of all net hits will count as a positive dice pool modifier when you later take backdoor entry tests on this host). Your dice pool (but not the opposed dice pool) is reduced by 1 dice for each repeated test you choose to take.
Note that if you fail a single opposed test then it seem as if the whole extended test fails (no matter how many net hits you had) and you have to start over (possible by activating the Trying Again rule or waiting for a longer period of time). Failing the test will not trigger any alarms (except maybe on glitch or critical glitch, this seem to be up to GM fiat).
Also note that the backdoor (your successful probe attempt) will vanish (fail) if you log out to reset your overwatch score between your successful probing and your backdoor entry attempt.