An old saying which always struck me as strange and misguided is "What you don't know can't hurt you". Of course what you don't know can hurt you, especially if it's an unseen oncoming vehicle, for example, or if you work in the cybersecurity space.
If you work in cybersecurity, the saying does not apply and will get you into trouble at some point. Nobody expects you to know everything, but they expect you to know what assets you have on your corporate networks plugged into your IT infrastructure. It's the first thing I look for when speaking to an organisation for the first time.
Generally speaking, the more that an organisation can tell you about their inventory of PC's, tablets, smartphones, servers, wireless access points and wireless access points, the better they are at cybersecurity. It may surprise you to discover that most organisations do not have a firm handle on their asset inventory.
This is shocking in itself because asset discovery is a foundational IT security measure and it's impossible to defend your IT infrastructure unless you have an up-to-date list of what you are defending. When you learn that most companies do not maintain an active list of their assets, it's not at all surprising that so many get breached.
When I talk to organisations about cybersecurity, I ask them questions like "what internet-facing assets do you have?", or "do you know where your data is and who has access to it" and if they scratch their heads a little piece of me dies inside.
I know that they will be vulnerable everywhere because they do not understand what they are defending. The single most effective cybersecurity action an organisation can make is to assign a dedicated person to estate discovery and maintaining an 'as close to real-time as possible' list of the company assets connected to their IT infrastructure.
If your organisation does not have a handle on the basics like asset inventory, whatever security tools you have in place are for show and a breach is just a matter of time, alarm bells should be ringing. Organisations are may find it tough to keep a handle on the number of PCs, BYOD hardware, servers, load balancers, firewalls and storage devices that connect to their networks, but when an unknown device is used to exfiltrate something valuable from your network, not knowing about it will not fly as an excuse.
The Breach Is Going To Be Your Fault
If you are unlucky enough to get breached and have the investigators discover that, you have no accurate asset inventory, the breach was your fault, and that's a concept even the C level will understand. Now that we have established that estate discovery is a fundamental piece of your IT security and that without it you will almost certainly get the blame for breaches, let's look at what you can do to get yourself out of this mess.
Immediately Eliminate Your Blind Spots - Let's be honest, you might know which PC's and employee mobile devices you have connected to your networks, but everything from random BYOD endpoints and IoT devices, to unauthorized SaaS applications, file sharing, and cloud storage is a potential blind spot. Your first step is to immediately eliminate all of those blind spots and you should view them as black holes full of security, legal and compliance risk that need to be plugged immediately if you are to remain compliant.
If You Do Not Have The Right Tools, Get Them - Your IT asset management tools let you detect things like servers, firewalls, load balancers and network storage, but what you really need is an automated tool that will give you visibility over every part of your network and ideally conforms to estate discovery best practices. Your solution needs to be able to scan your network address ranges and analyze traffic in order to identify unknown assets. It then needs to be able to drill down into those assets for granular information about connections, permissions, usage and tag the asset for future tracking.
Inventory & Control Your Hardware & Software Assets - You absolutely need to be actively managing (meaning tracking and keeping an inventory) of your hardware and software assets. Only authorized hardware can be given access to your networks and only authorized software can be installed onto your endpoints. You need to know which employees can use your hardware or software and know which users should not be accessing it and estate discovery can help you accomplish this.
Hire Or Appoint A Dedicated Asset Controller - This should go without saying, but you absolutely need to appoint somebody to assume responsibility for maintaining an accurate inventory of your assets, if you are to ever hope to get a handle on them in any way. This is the single most effective action that you can make in order to improve your overall cybersecurity posture, appointing a dedicated asset controller will yield a significant return on investment compared to almost anything else.
Consider Bringing In The Professionals - There is so much complexity to network topology, only so much time in your busy IT teams schedule and so many different tools on the market that it can be difficult for organisations to know which steps to take first and how to make them. If this is the case for your organisations, then your best bet is to bring in the professionals. I spoke to Marek Bialoglowy, the CTO of cybersecurity firm ITSEC and asked him how often they get called in to conduct estate discovery projects, he told me "a substantial part of our work is helping our clients work out exactly what they are defending and often they call us in to act as a force multiplier to their existing IT team and help them bring their asset management processes up to best practice".
Whichever route you take to discovering all of the assets connected to your networks, you absolutely need to start right now if you have not done so already. Estate discovery is such a fundamental tenet of IT security, that it must be prioritized and actively managed if you ever hope to properly secure your networks against a rapidly rising tide of cyber threats inevitably heading towards your organisation.