[BreachExchange] LinkedIn’s disturbing breach notice

[Audrey McNeil]

http://www.computerworld.com/article/3077478/security/linkedin-s-disturbing-breach-notice.html

Late last Wednesday (May 25), LinkedIn casually sent a note to its
customers that opened with one of the least-calming phrases possible: “You
may have heard reports recently about a security issue involving LinkedIn.”
It continued to say, in effect, “Let us now distort and misrepresent those
reports to make us sound as good as possible.”

The upshot of the notice was that LinkedIn was breached back in 2012 and
that much of that stolen information has now resurfaced and is being used.
>From the LinkedIn notice: “We took immediate steps to invalidate the
passwords of all LinkedIn accounts that we believed might be at risk. These
were accounts created prior to the 2012 breach that had not reset their
passwords since that breach.”

Before we delve into why this is potentially a big security problem, let’s
first examine what LinkedIn, by its own admission, did. About four years
ago, it was breached and knew about it. Why, in mid-2016, is LinkedIn only
now invalidating those passwords? Because until now, LinkedIn made it
optional for users to change their credentials.

Why in the world would LinkedIn have ignored the problem for so long? The
only explanation I can think of is that LinkedIn didn’t take the breach’s
implications very seriously. It is unforgiveable that LinkedIn knew that a
large segment of its users were still using passwords that it knew were in
the possession of cyberthieves.

The reason this is a potentially even worse situation is that we have to
look at who the likely victims are and what is truly at risk.

According to that LinkedIn breach notice, there were only three pieces of
information accessed by the thieves: “Member email addresses, hashed
passwords, and LinkedIn member IDs (an internal identifier LinkedIn assigns
to each member profile) from 2012.”

Presumably, the member ID would be useful to thieves trying to impersonate
members and access nonpublic info. For example, some members include
private/personal email addresses and phone numbers that can theoretically
only be seen by first-level contacts. There might also be a history of
searches performed or other information useful to an identity thief.

Why didn’t LinkedIn simply change all of the stolen member IDs back in
2012? That should have been within its power, and it could have cut off a
wide range of fraudulent possibilities. The fact that those numbers are the
same four years later is scary.

An email address on its own is a nice-to-have for identity thieves, but for
most people, it is a piece of data that is very easily found elsewhere,
since most people share theirs rather widely.

Clearly, the problem data point here is the passwords. This brings us back
to the “who are the victims here?” question. These are people who haven’t
changed their passwords in at least four years — even though there was
extensive coverage back in 2012 of this breach. The big problem is that
people who don’t change their passwords in these situations are likely to
overlap with another group of people: those who tend to reuse their
passwords.

So the thieves know that these passwords could quite easily get them into
places far beyond LinkedIn, such as bank accounts, retail shopping sites
and even the big enchilada for thieves: password-protection sites. What’s
the most dangerous password most people have? The one that unlocks dozens
of other passwords they have.

Why didn’t LinkedIn force its customers to change their passwords four
years ago, as soon as it learned of the breach? That is the question that
every LinkedIn customer must now insist be answered. And it has to be
answered before they decide to renew.
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