Friday, May 21, 2010

Temporal Proximity

A couple of years ago, I heard someone...a really smart someone...talk about "temporal proximity". I know that sounds Star Trek-y, but the reference was to initiating response activities as close to an incident as possible.

Several of the industry reports indicate that the majority of incidents that the vendors have responded to have been the result of third-party notification to the victim. That alone indicates a number of things, the lack of temporal proximity (perhaps a better description would be "temporal dispersion") being one of them.

Why is this so important? Well, a lot of good...no, strike that...a lot of critical information can exist in memory, making it very volatile. Processes complete, network connections terminate. The longer you wait, the more this happens...and the system is more likely to be rebooted.

Some intruders get on systems, run tools, and them leave with data. When they do so, they may delete their toolkits. I've seen batch files that include the "del" command for just that purpose. Well, the more temporal dispersion you have from the incident, the less likely you are to recover the deleted files...in case you haven't heard, Windows (especially XP) has it's own built-in antiforensics measures.

Okay, you're probably wondering what I'm talking about...so I'll tell you. For Windows systems, even if you don't interact with the system, stuff still happens, particularly with XP. Just let an XP system sit for a couple of days, and you'll see. Restore Points are created every 24 hours, and if the disk space available for the RPs is getting short, others will be deleted. A limited defrag is run every three days. And this is just for an XP system that sits there with no network connectivity and no one interacting with it. Now, add to that things like Windows software and application updates...you know, the stuff that just kind of happens automatically with a network connected system. Even with minimal auditing enabled, stuff still gets logged to the Event Log...more so on Vista and Windows 7, simply because there are so many more logs.

Now, add to the mix that no one within your infrastructure is aware of an incident (intruder, malware, etc.), and systems remain up, functioning, operational and in use. I've been on engagements where we collected data from a system and then three days later collected the same data...and you'd swear that they were two different systems. Prefetch files had been deleted, deleted files had been overwritten by OS and application updates, applications and tools being run, etc.

In order to achieve temporal proximity, you need a couple of things. First, visibility...if you don't have visibility into your infrastructure, how will you know when something occurs? You can't really expect to know when something goes wrong or changes if you're not monitoring, right?

Second, you need a plan. What's you're IR plan? Acquire memory and disk, and then take the system offline? Or panic and not do anything at all until someone who has no idea what's going on makes a decision? I can't tell you the number of times I've responded and found out that the incident had been detected a month prior, and the infected/compromised system had been left up the entire time.

Me: "You know the intruder has been siphoning data off of this system for the past month, right?"

Them: "We didn't know what to do."

This happens more than you'd care to know, and not just to one vertical...not just PCI, but to many, many types of victims.

One final note...Marines in training learn what are referred to as "immediate actions". These are simple tasks that you use to clear a jammed weapon. They're simple when you're on the range, on a bright, sunny day after a good night's sleep. You can ask a range coach if you're doing it right. But we're trained on this over and over because you never need it in those conditions...when you're going to need that reaction to be programmed is during an assault, at 2:30am, after you've gone without sleep for two or more days and maybe haven't eaten in as long. And it's raining. And it's cold.

Are your IT assets critical to your business? If I were to back up a truck and take all of your computers...all desktops, laptops, servers, etc...how would that affect your business? It would disappear, wouldn't it? Well, if IT assets are so critical to your business, why not protect them? The bad guys aren't coming into your organization and walking out with boxes full of papers...they're coming into your network and stealing data that way. And they're successful because in many cases, they have greater visibility into your infrastructure than you do.

2 comments:

Anonymous said...

Harlan, this is quite an interesting article. A little scary. I would think the upper echelons of of business would be proficient in 'covering their ASSets', and take a more proactive approach to IR. -daanday3953

Keydet89 said...

Daan,

The "upper echelons" are indeed proficient, but not as you suggest. In many instances, ignoring the issue or threatening legal action against someone is the modus operandi.