A few times over the years, I’ve had people ask me about the fabled silver bullet of security. “If I could just do one thing and be secure, what would it be?” I tried to give them some generic, easy to implement, high-yield concept like turn on MFA. But after considering that question for some time, I’ve thought of a different answer:
Common sense.
I can’t think of any one thing more important in the security arena than that. To be clear, there are two types of threats out there. There’s bad guys who use the spray and pray mentality of trying to attack as wide an audience as possible. Then there’s the advanced persistent threat (APT). I’m talking about the first category – which affects most of us. If you’ve got an APT, like a nation state on your tail, I only have one question for you: “What’d you do?”
When you’re looking at your email inbox and see a message that claims, “Here’s an Uber receipt for your recent trips in Berlin, Germany. If you didn’t do this click this link to dispute,” common sense is a great ally. I’ve trained myself to always hesitate before clicking any links in any email (from known people or not). A 5 second search on the internet “Uber scam email” revealed the common dispute clickbait that spoofs official Uber receipts.
Another one that almost got me was receiving an email from Xerox@[MyCompanyDomainName] that had a PDF attachment with the same file name as when you actually scan and email yourself from a Xerox printer. After a quick pause, I realized that those emails come from Helpdesk@[MyCompanyDomainName] (not Xerox) and the body of the email mentioned the printer model which we didn’t have in our environment.
I know both my examples have to do with email, but common sense is an invaluable skill throughout the industry. Whether you’re opening email, troubleshooting a TV in a conference room, or just trying to figure out the dynamics of a coworker relationship, train yourself to see those logical arguments. “Wait, if this is that, that wouldn’t be true. So, I know that can’t be it.”
Hopefully that’s helpful in your ongoing security journey!