Friday, November 20, 2009
10 Facebook Don'ts
Facebook is more popular than ever. The site frequently goes through
changes, but how many people use the same schedule of improvements on
their own profile? The new features added to Facebook are opening new
windows for vulnerability. A compromised account is a backdoor to more
serious attacks on email or banking.
Today I will show you 10 things
you should stop doing on Facebook in order to take back your security
and close the open door.
-Stop posting your phone numbers. Last week I explored a Facebook
attack that harvests the phonebook feature. Remember that your number
is exposed to your friends, and therefore you're relying on their
security practices as well as your own to protect you. If a phisher
can spoof your number, they have an extra layer of authenticity in
convincing your friends you are in trouble and need money fast.
-Put down the games. I know the Mafia can't take Cuba without you, but
it's time to stop. The top games on Facebook have been hacked, and
it's just a matter of time before the one you play is next. It's
arguable that the damage is already done with the games and
applications you've already allowed, but don't sign up for any new
ones! Third party apps are not guaranteed to be secure, and you should
not trust them with your credentials.
-Don't trust chat. It shouldn't take Chris Hansen to tell everyone that the person on the other end of your chat session could be anyone. The chat feature on Facebook should be treated as a public conversation. Never give out any private information, even if you're positive you are talking to your friend.
-Refresh your personal info. Take a fresh look at your profile from
the perspective of a social engineer. Does your profile tell a story
about you? What information can you cut out? Many security questions
ask about personal details about primary school and pets. Delete any
photos or profile details that may relate to those kinds of questions.
-Don't use the lazy emails. Facebook will fill your email inbox with
notifications, and the links to easily respond. Instead of following
the links in email, open up a fresh tab and go to facebook.com
directly. Facebook and most social networks are targets for email
spoofing. Otherwise you'll be entering your login password at
-Don't friend acquaintances. Think of the friends list as a circle of
trust. If you don't know the person well enough to trust their
security savvy, than you're very unlikely to recognize the behavior of
a phisher pretending to be them. 500 friends means 500 possible
inroads to a social engineering or phishing attack. Tone down the
-Don't keep an old password! Changing your password short circuits many trivial forms of attack. Facebook is a high risk target for Identity Theft, especially if you're using applications frequently. How about doing it now!
-Photos are forever. Make it clear to your friends and family that you do not want those pictures of you in your birthday suit on anyone's profile. (As opposed to the one of you in a suit on your birthday!) Pictures give behavioral information to an attacker. Bruce Schneier calls this "incidental data" in his Taxonomy of Social Networking Data. There he makes the assumption that incidental data is information that you did not create about yourself, and therefore do not control. I would add that although much of it is outside your control, there are ways to influence your friend's posting behavior overall. Also, Facebook gives users the ability to "untag" themselves in pictures. While the damage is already done in the short term, you've influenced long term vulnerability.
-Don't forget @mentions. This new feature brings more incidental data. Be respectful of your neighbor's privacy. Ask yourself if having a friend's entire profile pinned to your comment like a big arrow is actually necessary for the joke to be funny.
-Don't trust other websites. Facebook is everywhere now. The same trust rules apply to the Facebook Login feature that is spreading to other websites. If you don't trust the website you're on, then signing in with the Facebook credential does not give you an added layer of protection, but rather hands your password to strangers.
This list may seem counterproductive to the efforts Facebook makes to create a global connected community. While I am interested in being a part of such a community, I go into it with eyes open. Just like wearing a wallet belt when I go to huge tourist destinations, I want to be smart about visiting the hugely popular social networking sites online. It may not be the coolest thing to do, but in the end I found that my friends didn't even notice I had taken these safety precautions. Now the camera bag I stuffed in my shirt... that was a different matter.