There was an interesting comment posted to a discussion on
LinkedIn about my
blog post from last month about the ICS-CERT report on the Ukraine power
outage in December. In that post I complained about the amount of time it was
taking ICS-CERT to make a public disclosure about the indicators of compromise
for that attack. I was making the point that the IOC could be used by control
system engineers and security specialists here in the US to prevent similar
types of attack.
One of the comments came from a young European researcher
who is making a name for herself in looking at control system security
vulnerabilities in manufacturing processes, particularly chemical processes.
Marina Krotofil noted that the ICS-CERT team that went to the Ukraine to look
at the investigation into that incident probably had to sign a non-disclosure
agreement with the government of the Ukraine before they were allowed access to
ask their questions. She suggested that that could be the reason that ICS-CERT
has not publicly listed the IOC for the incident.
Neither of us knows that that is the case, but it would
certainly seem to be a reasonable action for the affected government to take.
IOC and other critical details about the attack on their power companies and
the response to that attack are properly their information to release. The fact
that there is more information available from various private security research
firms probably means that they are more experienced at negotiating the terms of
an NDA with foreign governments or directly with foreign utilities than is the
ICS-CERT.
I am still concerned that the IOC are not being made
available to the potentially affected organizations here in the US (other
countries should have their own bloggers pounding the same table), but I am
willing to concede that ICS-CERT may be legally restricted from sharing that
information.
Another interesting take away from this discussion is that
NDA’s with foreign governments will not be the only restrictions on sharing
actionable intelligence from control system security incidents. Under the
information sharing program mandated by Congress last year, companies sharing
information with DHS about cyber incidents can put the same sort of
restrictions on sharing that information outside of the government.
Again, I can clearly understand why that provision was
included. Without that caveat there are many organizations that would not share
incident information with the government. Either out of embarrassment for lax
security controls, worry about the effect on investor confidence, or even just
out of a basic desire to keep private activities private, many companies would
prefer not to share information with the government, much less see that
information spread before the world.
Organizations like ICS-CERT are going to have to come up
with ways to sterilize the information passed to DHS in such a way that
actionable intelligence on IOC and attacker methodologies can be distributed to
a wider audience without upsetting the sensibilities of board rooms.
One way to deal with this could be to do with known malware
that is involved in attacks what ICS-CERT has done with Black Energy that was
apparently used in the setup of the attack in the Ukraine. ICS-CERT published
YARA rules for detecting that malware and encouraged the reporting of
indicators from applying those rules to control system networks. Then when ICS-CERT
receives notice of a Black Energy compromised system, they can deploy an away
team or contractors that have been taught how to detect the IOC from the Ukraine
attacks in their investigation of the potentially compromised system. Attacks
could be caught early and appropriately mitigated and friendly nations or
companies could feel safe that their dirty security laundry has not been shared
with the public.
I would still prefer to see public disclosure of IOC, but
when that cannot be done we need to be confident that someone with the
knowledge gained from known attacks can respond to help system owners prevent
similar attacks on their organizations.
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