Recently, I was asked by an instructor at a technical college if I would mind responding to some of his students' questions. I happily agreed. Ultimately, this resulted in a lively back-and-forth session, so I decided to share the exchange with you. Enjoy!Question 1: Microsoft just announced a huge list of security patches for "Patch Tuesday." Why doesn't it just focus on a single product and fix all of the security holes in one shot? Finding bugs in products doesn't work that way. Every product that Microsoft codes goes under dozens of manual and automated tool reviews. That scrutiny is vital because Microsoft is the biggest target, and as a result Microsoft products actually have fewer vulnerabilities than those of its nearest competitors. But even with the right tools and processes, you can't catch everything. New techniques are found, mistakes are made, and until you have perfect humans, you'll never have perfect code and you'll never have perfect bug detecting.[ Find out how to block the viruses, worms, and other malware that threaten your business with hands-on advice from InfoWorld's expert contributors. Download the PDF today! | Stay up to date on the latest security developments with InfoWorld's Security Central newsletter. ]Here's a good example. Years ago someone discovered they could buffer-overflow the HTLM color attribute field located on Web pages as it was rendered in a popular browser. No browser vendor at the time ever thought the color attribute field could be abused. The vendor's security reviewers didn't know to look for it and neither did any of the private or third-party tools, despite the fact that every field should be boundary-tested. Now all vendors check for it. Everything looks easier in hindsight -- improving software is an evolving process.Question 2: In one of your blog posts, you mentioned something like: "The NSA could be hiding small snooping programs in, let's just say, a picture of a cute kitten or a fun Android game." So how can the average Joe ever know that what they download is the real picture or app with no hidden malware in it? The short answer is you can't -- not even close. The only thing you can do is decide to trust the entity that created the device or code, especially if it is digitally signed. Because as long as their digital-code signing cert wasn't compromised or the machine the code was signed on wasn't compromised, at least you can say that the code the developer signed was what they signed when they signed it. But the truth is you really don't know.It's all a matter of faith and trust. Certainly some vendors deserve more trust than others. Personally, I believe we need to "fix" the Internet and make hacking and snooping, even by the NSA, easier to prosecute and easier to detect. It disturbs me greatly that what the NSA does is completely legal ... and most countries don't even have the laws that we do. I wish everyone's privacy laws were stronger. In the United States, we need to modify our Constitution to guarantee more personal privacy. I thought the amendment against unreasonable search and seizure did that, but it's not even close to being enough these days.Question 3: I liked your article "Crazy IT security tricks that actually work." Someone dismissed your points of "security through obscurity." If these things work, then why would the IT Industry be so quick to discount them?People repeat dogma as fact, when all you're really talking about are cute little sayings that were a stretch from the beginning. Obscurity is one part of security. It shouldn't be relied upon as the only defense, but it certainly plays a big part. If it didn't, every army would tell the other army what all their capabilities were, where all the weapons and troops were, and make everything "transparent."The best thing I can say to anyone trying to learn is not to accept everything you hear at face value. Respect what other, more learned people say, but don't accept anything as gospel unless you do it or see it yourself. Stay skeptical.Question 4: If Stuxnet was the most complex piece of malware ever created, then couldn't the "sons of Stuxnet" wreak havoc across all of the Internet and not just at the Iranian nuclear facility? This is a huge, huge fear of a lot of people. However, I expect that one day a much less complex piece of malware will "crash" the Internet. Sophisticated malware is needed only for sophisticated scenarios. Crashing the Internet or stealing from banks is easily accomplished with conventional malware. Hackers are likely stealing tens of millions of dollars every day, if not hundreds of millions. They are allowed to get away with it, and the public accepts it as a cost of doing business because they stay below a certain threshold. One day one of them will make a mistake, steal too much, and the world will freak out and finally fix the Internet.Question 5: It has been widely reported that the NSA put backdoors into a bunch of different programs. How do we know these backdoors have been closed? Most of them probably haven't been closed. Until we get their complete list of software exploits, which is highly unlikely, we'll never be able to do it. And it's not just the NSA you have to worry about, but every sophisticated government and hacker group. Software is full of exploitable holes that only certain people have knowledge of.Question 6: We're being taught to hack. What is to stop us from being evil with the knowledge we've been given? Hacking is actually fairly easy. It's like a cookbook recipe: Once you know how to hack, it's mostly a repeatable process. Most hackers simply mimic what someone else did. They seldom think of anything new. You want to impress me? Do something new. Most hackers are followers.The smartest hackers are the good guys. It's easy to hack; it's much harder to defend. It's easy to tear down a barn with a saw and a sledgehammer; it's much harder to build the barn. It's even more impressive to build a barn that can resist the saw and the sledgehammer.You shouldn't hack illegally for the same reason you shouldn't assault someone. It's morally wrong. I've had the skills to hack illegally for over two decades. I get paid to hack legally all the time. Over the past nine years it's never taken me more than an hour to break in (except one time, when it took me three hours). This includes banks, hospitals, government agencies, and Fortune 500 companies. It's not that hard to hack. And guess what? I make a very good living -- far better than I could ever have imagined. I am living the dream.Legal hacking allowed me to accomplish this, and I don't have to worry about the feds arresting me. If you go the illegal route, it's going to catch up with you eventually. It always does. You can make more money and sleep well at night by hacking legally. You'll have a better career and a better life doing the right thing.Question 7: I read that no matter how long or complex your password is, that it can be broken by a pass-the-hash attack. True? In a sense. PtH (pass-the-hash) attacks require that the attacker obtain local administrator status on the box they are stealing hashes from (or obtain domain administrator on a domain controller). If you have that sort of access, then what can't you do?That said, if attackers steal the ultimate authentication secret -- for example a password, a password hash, a Kerberos token, a ticket, and so on -- they have the ultimate authentication they need to do almost anything. Length of password, hash, digital certificate key, and so on will not protect you.PtH attacks are a valid concern, but if they went away completely (Windows Server 2012R2 has plenty of PtH defenses built in), it would not stop attackers in the slightest ... because they already own the box. They can just do keylogging, Trojan the machine, or modify the operating system. We should be more concerned about how attackers get that elevated access in the first place, not focused on what they do with it once they have that access. ... Because sky is the limit and there is no defense.Question 8: Is the NSA leaker a hero or a traitor? He's a bit of both. Ultimately, he broke his NDA and many laws. He has put other people's lives at risk. He should be punished for that. The only rationale to do what he has done is if what you are revealing is illegal or unconstitutional. So far nothing he has revealed is either of those things. Nothing he has revealed is a surprise to those of us who follow the NSA.Just read any James Bamford book. He was writing about the NSA's capabilities 25 years ago. The only new things that he revealed, to those of us who follow the NSA, is names of programs and perhaps some individual exploits.That said, he is to be applauded for bringing the excesses of what the NSA is legally allowed to do to the public masses. I'm hoping that everyone being upset with the NSA will lead to laws being changed, so the NSA cannot legally collect everything they are already collecting. It upsets me, and others, that it took a single employee breaking the law to make the rest of the world up in arms about something we've known for years if not decades.Question 9: We discussed the FBI takedown of the Silk Road in class and I was wondering: If the NSA has all of the access to our personal lives, why did it take the FBI three years to take them down? Law enforcement is always slow, especially when it crosses multiple jurisdictions. It takes time to start legal projects, collect evidence, obtain warrants, and proceed. But I suspect that most of the time was spent just getting on the FBI's already busy radar. The FBI, like your own company, has a budget and a project plan each year. I bet Silk Road wasn't on the radar until enough people started complaining. Plus, many times the investigation goes on far longer than what's needed to collect evidence, as perpetrators go after bigger targets and commit more crimes, resulting in easier-to-prove court cases and longer jail sentences.Also, the NSA and the FBI don't always share information. The NSA, for the most part, doesn't care about drug trafficking, money laundering, theft, and a lot of the other things the FBI cares about. As bad as our laws are, the NSA can't simply share what it has with other legal entities.Question 10: I want to work in information security, first as an administrator then ultimately as a consultant. What is the best certification to pursue? I have about 50 certifications, and I learned something new from each one of them. Each cert made me a more knowledgeable technician, and each gave me something that made me more employable. But if you're talking about which ones count the most, that's a slightly different answer: It's the certification most relevant to your potential employer or its customers.Fortunately or unfortunately, experience counts more. Because of that, you want to pick certs that give you both credentials and real hands-on experience. I like the CompTIA stuff. It teaches a lot. But their certs are basically thought of us "base" certifications. When you earn one of those, you know the basics. Still, great to know, and you will learn something.Personally, I'm not a huge fan of the CISSP (because it's a lousy test), but it's probably the one cert that most employers and clients like to see. I think it's because bosses and clients often have it and think it was hard, so they like to know other people they are hiring had the same hard time with it.I'm a huge fan of anything SANS does or offers. I think the SANS courses, books, instructors, and certs teach you more hands-on experience than any of the other relative certs. When I see someone with a SANS cert, I immediately trust them. It's the security geek's CISSP. I also like the CEH and other certified auditor exams. Each has its benefits. Each teaches you something.Question 11: What kind of tools should I run to make sure my PC is clean (or as clean as possible)? I never recommend a particular product. They are all fairly accurate, and they all fail miserably on a daily basis. Don't believe any of the "accuracy tests" you read. It's not that the tests are inaccurate, it's that they often set specific parameters that (accidentally or otherwise) benefit particular products.I've been in the AV field since 1987. Accuracy goes up and down on every product over time. Just pick one that is reasonably accurate and one that doesn't kill your system's performance. You should run AV, but remember that 99 percent of all successful exploits are caused by unpatched software.Question 12: How can I detect if my computer has been turned into a bot to help perpetrate a DDoS attack? It can be hard, especially if your computer has been hit with a rootkit. AV is supposed to detect that sort of stuff, but it often misses it. I love to do two things to look for bot programs myself. First, I use the free utility Autoruns. It will show you everything that is running when your PC starts. It will be a hundred things. Research anything you don't recognize. When in doubt, uncheck the program and reboot. If it breaks something, run Autoruns again and recheck.Second, download TCPView from Sysinternals. Close every program you think could possibly be communicating with the Internet. Then run TCPView. Research any programs or processes that are communicating with the Internet. Most of the time you'll see one or more things connecting to the Internet that you didn't know about. This is normal. Usually they are just legitimate programs connecting back to the vendor doing something the vendor programmed them to do. Research the destination connection points. If you can't figure out what the program is connecting to and whether it is legitimate, consider using Autoruns to disable it.But the truth is that malware programs can be very difficult to discover and remove. When in doubt, back up all your data, reformat (or reset), and reinstall everything again. This is the only way to truly know that you are starting with a clean state.Question 13: I use a MacBook Pro. I know it is built on Darwin Unix, but is it truly more virus-resistant than Windows 7 or 8? Yes and no. No, in that OS X has far more vulnerabilities than Windows -- and I don't mean a little. Windows gets about 120 to 200 bugs a year. OS X gets two to three times as many, if not more.With that said, because OS X runs on only 5 to 10 percent of the world's computers, it still isn't a very big target. Bad guys target popular things because they are more likely to get something of value. Running OS X will probably incur less risk compared to a Windows computer -- probably significantly less risk.Note that computer viruses aren't nearly as common as worms, Trojans, and other sorts of malware. Use the term "malware" or "malicious program" instead of "virus." Virus indicates only one type of malware.This story, "13 tough questions about computer security," was originally published at InfoWorld.com. Keep up on the latest developments in network security and read more of Roger Grimes' Security Adviser blog at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter.