Check that- security is relatively hard in static environments, but when you take on a dynamic company environment security becomes unpossible. I'm injecting a bit of humor here because you're going to need a chuckle before you read this.
Some of us in the security industry live in what's referred to as a static environment. Low rate of change (low entropy) means that you can implement a security control or measure and leave it there, knowing that it'll be just as effective today as tomorrow or the day after. Of course, this takes into account the rate at which effectiveness of security tools degrades, and understanding whether things were effective in the first place. It also means that you don't have to worry about things like a new system showing up on the network very often or a new route to the Internet. And when these do happen, you can be relatively sure something is wrong.
Early on in my career I worked for a technical recruiting firm. Computers were just a tool and companies having websites was a novelty. The ancient Novell NetWare 3.11 systems had not seen a reboot in literally half a decade but nothing was broken so everything just kept running and slowly accumulating inches of dust in the back room. When I worked there we modernized to NT 3.51 (don't laugh, I'm dating myself here) and built an IIS-based web page for external consumption. That place was a low entropy environment. We changed out server equipment never, and workstations every 5 years. If all of a sudden something new showed up in the 30 node network, I'd immediately suspect something was amiss. At the time, nothing that exciting ever happened.
Fast forward a few years and I'm working for a financial start-up. It's the early 2000's and this company is the polar opposite of a static company. We have at least 1 new server coming online a day, typically 5-10 new IP addresses showing up that no one can identify. We get by because we have one thing going for us. That one thing is the on-ramp to the Internet. We have a single T1 which connects us to the rest of the world. We drop a firewall and an IDS (I think we used an early SNORT version, maybe, plus a Sonic Wall firewall). When that changed and our employees started to go mobile and thus VPN things got a little hairy.
Fast forward another few years and I'm working at one of the world's largest companies on arguably one of the most complex networks mankind has ever seen. Forget trying to understand or know the everything - we're struggling to keep track of the few things we DO know. Heck we spend 4 weeks NMap'ing (and accidentally causing a minor crisis, oops) our own IP subnets to find all the NT4 systems when support finally and seriously for real this time, ran out.
Now let's look at security in the context of this article (and reported breach) - http://www.nextgov.com/cybersecurity/2014/10/dhs-attackers-hacked-critical-manufacturing-firm-months/96317/. Let me highlight a few key quotes for you-
"The event was complicated by the fact that the company had undergone corporate acquisitions, which introduced more network connections, and consequently a wider attack surface. The firm had more than 100 entry and exit points to the Internet."You may chuckle at that, but I bet you have pretty close to this at your organization. Sure, maybe the ingress/egress points you control are few, and well protected, but it's the ones you don't know about which will hurt you. Therein lies the big problem - the disconnect between business risk and information security ("cyber") risk. If information security isn't a part of the fabric of your business, and a part of the core of the business decision-making process you're going to continue to fail big, or suffer by a thousand papercuts.
While not necessarily as sexy as that APT Defender Super Deluxe Edition v2.0 box your vendor is trying to sell you, network and system configuration management, change management and asset management are things you absolutely must get right, and must be involved in as a security professional for your enterprise. The alternative is you have total chaos wherein you're trying to plug each new issue as you find out about it, while the business has long forgotten about the project and has moved on. This sort of asynchronous approach is brutal in both human effort and capital expenditure.
Now let's focus on another interesting quote from the article. Everyone like to offer advice to breach victims, as if they have any clue what they're saying. This one is a gem-
"Going forward, “rearchitecting the network is the best approach to ensure that the company has a consistent security posture across its wide enterprise," officials advised."What sort of half-baked advice is that?! Those of you who have worked incidents in your careers, have you ever told someone that the best thing to do with your super-complex network is to totally rearchitect it? How quickly would you get thrown out of a 2nd story window if you did? While this advice sounds sane to the person who's saying it - and likely has never had to follow the advice - can you imagine being given the task of completely rearchitecting a large, complex network in-place? I've seen it done. Once. And it took super-human effort, an army of consultants, more outages than I'd care to admit, and it was still cobbled together in some places for "legacy support".
Anyway, somewhere in this was a point about how large, complex networks and dynamic environments are doomed to security failure unless security is elevated to the business level and becomes an executive priority. I recognize that not every company will be able to do this because it won't fit their operating and risk models - but if that's the case you have to prepare for the fallout. In the cases where risk models say security is a business-level issue you have a chance to "get it right"; this means you have to give a solid effort and align to business, and so on.
Security is hard, folks.