Shostack + Friends Blog Archive

 

FBI says their warnings were ignored

There’s two major parts to the DNC/FBI/Russia story. The first part is the really fascinating evolution of public disclosures over the DNC hack. We know the DNC was hacked, that someone gave a set of emails to Wikileaks. There are accusations that it was Russia, and then someone leaked an NSA toolkit and threatened to leak more. (See Nick Weaver’s “NSA and the No Good, Very Bad Monday,” [link to https://www.lawfareblog.com/very-bad-monday-nsa-0 no longer works] and Ellen Nakishima’s “Powerful NSA hacking tools have been revealed online,” where several NSA folks confirm that the tool dump is real. See also Snowden’s comments “on Twitter:” “What’s new? NSA malware staging servers getting hacked by a rival is not new. A rival publicly demonstrating they have done so is.”) That’s not the part I want to talk about.

The second part is what the FBI knew, how they knew it, who they told, and how. In particular, I want to look at the claims in “FBI took months to warn Democrats[…]” at Reuters:

In its initial contact with the DNC last fall, the FBI instructed DNC personnel to look for signs of unusual activity on the group’s computer network, one person familiar with the matter said. DNC staff examined their logs and files without finding anything suspicious, that person said.

When DNC staffers requested further information from the FBI to help them track the incursion, they said the agency declined to provide it.
[…]
“There is a fine line between warning people or companies or even other government agencies that they’re being hacked – especially if the intrusions are ongoing – and protecting intelligence operations that concern national security,” said the official, who spoke on condition of anonymity.

Let me repeat that: the FBI had evidence that the DNC was being hacked by the Russians, and they said “look around for ‘unusual activity.'”

Shockingly, their warning did not enable the DNC to find anything.

When Rob Reeder, Ellen Cram Kowalczyk and I did work on usability of warnings, we recommended they be explanatory, actionable and tested. This warning fails on all those counts.

There may be a line, or really, a balancing act, around disclosing what the FBI knows, and ensuring that how they know it is protected. (I’m going to treat the FBI as the assigned mouthpiece, and move to discussing the US government as a whole, because otherwise we may rat hole on authorities, US vs non-US activity, etc, which are a distraction). Fundamentally, we can create a simple model of how the US government learns about these hacks:

  • Network monitoring
  • Kill chain-driven forensics
  • Agents working at the attacker
  • “Fifth party take” where they’ve broken into a spy server and are reading what those spies take.*

*This “fifth party take”, to use the NSA’s jargon, is what makes the NSA server takeover so interesting and relevant. Is the release of the NSA files a comment that the GRU knows that the NSA knows about their hack because the GRU has owned additional operational servers?)

Now, we can ask, if the FBI says “look for connections to Twitter when there’s no one logged into Alice’s computer,” does it allow the attacker to distinguish between those three methods?

No.

Now, it does disclose that that C&C pathway is known, and if the attacker has multiple paths, then it might be interesting to know that only one was detected. But there’s another tradeoff, which is that as long as the penetration is active, the US government can continue to find indicators, and use them to find other break-ins. That’s undeniably useful to the FBI, at the cost of the legitimacy of our electoral processes. That’s a bad tradeoff.

We have to think about and discuss priorities and tradeoffs. We need to talk about the policy which the FBI is implementing, which seems to be to provide un-actionable, useless warnings. Perhaps that’s sufficient in some eyes.

We are not having a policy discussion about these tradeoffs, and that’s a shame.

Here are some questions that we can think about:

  • Is the model presented above of how attacks are detected reasonable?
  • Is there anything classified which changes the general debate? (No, we learned that from the CRISIS report.)
  • What should a government warning include? A single IOC? Some fraction in a range (say 25-35%)? All known IOCs? (Using a range is interesting because it reduces information leakage back to an attacker who’s compromised a source.)
  • How do we get IOCs to be bulk declassified so they can be used at organizations whose IT staff do not have clearances, cannot get clearances rapidly, and post-OPM ain’t likely to?

That’s a start. What other questions should we be asking so we can move from “Congressional leaders were briefed a year ago on hacking of Democrats” to “hackers were rebuffed from interfering in our elections” or, “hackers don’t even bother trying to attack election?”

[Update: In “AS FBI WARNS ELECTION SITES GOT HACKED, ALL EYES ARE ON RUSSIA“, Wired links to an FBI Flash, which has an explicit set of indicators, including IPs and httpd log entries, along with explicit recommendations such as “Search logs for commands often passed during SQL injection.” This is far more detail than was in these documents a few years ago, and far more detail than I expected when I wrote the above.]