Virus activity: no know BlackBerry viruses to date.
Phishing:that's social engineering. If you are dumb enough to fall for a Nigeria scam, the BB won't help you
Corporate Hacking: Password protect your BB. Don't lose it. No hacking.
The BlackBerry itself is very safe. It the user who normally has the problem...
The BlackBerry is not a PC. It doesn't run Windows.