Shostack + Friends Blog

 

Modeling Attackers and Their Motives

There are a number of reports out recently, breathlessly presenting their analysis of one threatening group of baddies or another. Most readers should, at most, skim their analysis of the perpetrators. Read on for why.

There are a number of reports out recently, breathlessly presenting their analysis of one threatening group of baddies or another. You should look at the reports for facts you can use to assess your systems, such as filenames, hashes and IP addresses. Most readers should, at most, skim their analysis of the perpetrators. Read on for why.

There are a number of surface reasons that you might reject or ignore these reports. For example, these reports are funded by marketing. Even if they are, that's not a reason to reject them. The baker does not bake bread for fun, and the business goal of marketing can give us useful information. You might reject them for their abuse of adjectives like “persistent”, “stealthy”, or “sophisticated.” (I'm tempted to just compile a wordcloud and drop it in place of writing.) No, the reason to only skim these is what the analysis does to the chance of your success. There are two self-inflicted wounds that often happen when people focus on attackers:

  • You miss attackers
  • You misunderstand what the attackers will do

You may get a vicarious thrill from knowing who might be attacking you, but that very vicarious thrill is likely to make those details available to your conscious mind, or anchor your attention on them, causing you to miss other attackers. Similarly, you might get attached to the details of how they attacked last year, and not notice how those details change.

Now, you might think that your analysis won't fall into those traps, but let me be clear: the largest, best-funded analysis shops in the world routinely make serious and consequential mistakes about their key areas of responsibility. The CIA didn't predict the collapse of the Soviet Union, and it didn't predict the rise of ISIS.

If your organization believes that it's better at intelligence analysis than the thousands of people who work in US intelligence, then please pay attention to my raised eyebrow. Maybe you should be applying that analytic awesomesauce to your core business, maybe it is your core business, or maybe you should be carefully combing through the reports and analysis to update your assessments of where these rapscallions shall strike next. Or maybe you're over-estimating your analytic capabilities.

Let me lay it out for you: the “sophisticated” attackers are using phishing to get a foothold, then dropping malware which talks to C&C servers in various ways. The phishing has three important variants you need to protect against: links to exploit web pages, documents containing exploits, and executables disguised as documents. If you can't reliably prevent those things, detect them when you've missed, and respond when you discover you've missed, then digging into the motivations of your attackers may not be the best use of your time.

The indicators that can help you find the successful attacks are an important value from these reports, and that's what you should use them for. Don't get distracted by the motivations.