Original URL: https://www.theregister.com/2011/07/05/blacklist_culture/
Burnish your blacklists to patrol internet access
Stop them at the gates
Posted in Software, 5th July 2011 15:00 GMT
Desktop What makes PCs so popular is the range of software you can run on them. But, as always, with great power comes great responsibility. And one of the first decisions you need to make about your desktop estate is who you give the power to.
Some users may well benefit from full admin privileges, given the range of "revolutionary" tools they will be chasing you to install. But such privileges, even if temporary, need to come with a serious dose of education.
Otherwise you will find them installing everything from malware to network hogs and anything in between, none of which will make your life any easier.
Crash and burn
In some respects, then, it is good news that software that insists on running in admin mode is much less common. Thanks to a combination of developer education and user complaints about the inconvenience of privilege elevation in Vista and Windows 7, badly written software, whether malicious or not, is still the main reason Windows PCs crash.
In fact, a Forrester survey shows that 13 per cent of system crashes are caused by poor software – and that’s legitimate software.
These days, most malware is written to steal information or money undetected, lying dormant for weeks or months and trickling out information rather than drawing attention to itself by causing mischief. To avoid detection many bots actually remove competing malware or patch the holes it uses.
Unauthorised legitimate software is hard to find too. With everything from Skype to BitTorrent using port 80 so it looks like a web page to a firewall, you will have to invest in deep packet inspection and content filtering if you want to block malware and lock down apps (or secure the data in them) by detecting their network connections.
Creative auditing
Even if you are doing that for security, you will need software auditing. You need to know what software is installed in your business and who is using it for several reasons: so that you can support them, so that you are not liable for running applications you don’t have licences for, and so that you are not paying licence fees for more copies of an application than anybody uses.
Discovering that all your business units are buying different versions of Adobe’s Creative Suite, for example, and that most of them need only two or three of the applications in there, means you can rationalise licences, saving more than enough to pay for the auditing tools and the time you spend auditing.
Don’t forget to check where software is being bought. Pirated software is not just a licence headache, it might not use the same code as the legal version.
Unless you are in a business where unleashing the creative whims of your employees is a way of making money, the next step is controlling who can use what applications.
It is most efficient to do that according to management groups and roles. So unless they are also designing a company newsletter, receptionists probably don’t need those expensive Adobe licences on their PCs, and they certainly don’t need CAD software.
It's in black and white
The question is whether to go for a whitelist – everything that is not explicitly permitted is denied – or a blacklist – everything that is not explicitly denied is permitted.
Built-in Windows tools like AppLocker, centralised management tools and streaming software virtualisation all give you the option to do either, so it may be the culture of the business that most affects which you choose.
With a blacklist it is impossible to block everything you might need to be worried about, but you don’t have to stay on top of new programs users need because they won’t be blocked; equally, you won’t be protected from them.
You could be driving users to running apps from USB sticks
With a whitelist, unless you are in a heavily regulated industry you need to tread carefully and be proactive about approving applications as they are released. Otherwise you could be causing productivity problems, driving users to cloud services or to running apps from USB sticks to get their jobs done.
Fun and games
In reality you need a combination of both approaches. You may whitelist all programs from certain publishers but block specific groups from using specific applications from those publishers, as well as blacklisting applications you don’t want anyone to use.
With what Palo Alto Networks calls a next-generation firewall, you can extend that way of thinking to online services such as Webex.
You could whitelist the Webex application and allow online meetings with PowerPoint sharing and instant messaging but not file transfer. Or let employees network on Facebook but not waste time playing Facebook games.
There’s plenty of technology for managing apps on desktops. What is needed is putting thought into the right policies. ®