OK, My hacking on the fly can overcome the device with an extended test versus the device firewall. Given who they are, I think it is safe to assume they have good stuff, so consider a firewall of 6. I have Hacking 4 + Exploit 4 + Hot SIM 2 = 10 dice to overcome the firewall and the time for each attack is 1 combat round. Basic access to the device is against the firewall, security access is firewall + 3 and admin access is firewall +6. I do not see it in the rules, but any ECCM the device has would raise the score. In the scenario we might be looking at, I would need to get twelve hits to get admin access., which probably doable in three rounds. The device gets a roll each turn to get past my stealth, which is only 4. I do not see that I get any mods to that number, so it is quite likely that I would be detected on the first attack, and almost certainly by the second.
This is all doable but would mean that I need to go to Hot SIM for my best chance, meaning that I would need to be left somewhere. I am willing to do this if you want me to.