Thursday, August 11, 2011

Has Facebook got your mobile number? Now your friends do too

Has Facebook got your mobile number? Now your friends do too: "
I'm sitting here in a hotel working on a Request For Proposal for full disk encryption while listening to a movie in the background. (It helps me think.) I take a peek at the Facebook feeds and, lo and behold, my wife is blasting out some fresh Facebook privacy angst!

Keep in mind, she's not a security pro and can barely spell HTML. To see her concerns about what you are about to read will surely evoke some emotion:

Jenny's Facebook post


WTF FACEBOOK! ALL THE PHONE NUMBERS IN YOUR CELL PHONE are now on Facebook. No joke -Go to the top right of the screen, click on Account, then click on Edit Friends, go left on the screen and click on Contacts. All phone numbers from your cell phone (FB friends or NOT) are published. There is an option on the right to disable. Feel free to repost this on your status, so your friends can remove their numbers and thus prevent abuse if they do not want them published.

Her Facebook post contains the steps you need to take to reveal the mobile numbers of your friends along with anyone you are friends with that you really don't know.

In the event you feel that this is not a privacy risk, let's put this into perspective based on how I use Facebook.

I have just under 1,400 Facebook friends. Most of them are a result of playing, dare I admit, Mafia Wars. Even though I stopped playing over a year ago, I still have lots of Facebook friends as a result.

I clicked on 'Account' -> 'Edit friends' -> 'Contacts' - and there they were: the mobile numbers of 213 friends. I estimated that about fifteen are people I know well, and a good number more are former or current colleagues.

I compiled a list of graphics pointing to some of my Facebook friends whose mobile numbers are now visible to me, even though they almost certainly never intended to share them. I smudged their mobile numbers to respect their privacy.

David's Facebook contacts

Here's what I think could have happened.

Some time ago, Facebook started posting messages on users' accounts saying that their account protection status was 'very low', and they should increase their protection.

Your account protection status: Very low

Naked Security criticized Facebook at the time for using what we thought were scare tactics to encourage users to give Facebook alternative email addresses and mobile phone numbers.

Facebook's thinking was that if users lost control of the email account they normally use to log into the social network with, there would be an alternative contact point which could be used to regain access.

That's fair enough if you're comfortable with sharing that additional information with Facebook - we just didn't like their wording which gives users the impression that there's something seriously wrong with how they have defended their Facebook account.

But what if you did follow Facebook's recommendation and gave them your mobile phone number to enhance your account's security?

Facebook add mobile phone

Once you've confirmed the mobile phone is in your possession, Facebook craftily includes a setting (already enabled) sharing your mobile phone number with your Facebook friends.

Option enabled

In other words, regardless of how you had previously set up the privacy settings for your mobile number - it's now been over-ridden..

Facebook mobile privacy setting

.. and your Facebook friends can now see your mobile number in their Facebook phonebook.

Facebook phonebook

In fairness to Facebook, it was you the user who agreed to this in the first place. Although you might not have liked them enabling this option by default after supposedly enhancing your account's security, you did allow it to happen.

My advice is to consider doing the following:

Remove other people's mobile phone numbers that you may have imported, using the steps given by Facebook. You'll still see the phone numbers of Facebook friends who have chosen to share their contact details.

Some of your Facebook friends may be listed in your phone book because you synched your Facebook account with your iPhone or Android smartphone using the Facebook app.

Be sure to tell your smartphone not to sync with Facebook in future if you're not comfortable with this and, at the same time, you should disable Facebook's ability to email your non-Facebook contacts with a reminder to join Facebook every two weeks.

Finally, check the privacy settings on your own account to prevent others from seeing your phone number.

And what about the next cool Facebook feature? Should users simply get used to this sort of thing?

No! Facebook, if being here for the long-haul is your plan, upsetting users like Jenny is not the way forward.

Most of your users are much like Jenny. She treasures her privacy; so should you.

Asking your users to opt in when new features and services become available is a much better approach to keep them happy and using your services than forcing them to opt out.

If you're on Facebook, and want to keep informed about the latest security threats, I would recommend joining the Sophos page on Facebook where we have a community of more than 100,000 people.

Follow @DSchwartzberg

Update: Thanks to readers for their comments below! I've updated the article above to reflect the advice regarding synching of contacts, and additional steps for resolving the issue.

Furthermore, check out Facebook's own statement on the scare.



"

Friday, August 5, 2011

Facebook 'Girls Must Be Watch Out Of Her mind' photo-tagging scam - the lessons to learn

Facebook 'Girls Must Be Watch Out Of Her mind' photo-tagging scam - the lessons to learn: "
Naked Security readers have asked us once again to warn of a rapidly-spreading photo-tagging scam on Facebook, this time with the grammatically curious title This Girls Must Be Watch Out Of Her mind After Making This Video.

Here's one wise Facebook user's advice:



We first wrote about this sort of scam back in April. Just look at the Request for Permission dialog from a typical rogue application:



Let's look at those permissions:

* Access my basic information. That seems OK, since you're agreeing to share information which you've shared already.

* Post to my Wall. This lets an application act as if it were you. Think about this: it can post anything, about anyone, linking to anywhere, in your name. You are giving the application the right to offer statements and opinions on your behalf, without asking you. That's an awful lot of power.

* Access my data any time. Combined with the previous permission - to speak on your behalf - this is very close to giving the application a power of attorney over your Facebook account. Do you ever really want to do that?

* Access my photos and videos. This effectively removes any privacy controls you enjoy over images of your personal life.

Now that Facebook has universally enabled its facial recognition service, whereby your friends can tag you in photos in which Facebook suggests you appear, photo-tagging has really taken off.

And a new way of abusing the abovementioned power of attorney is open to rogue Facebook applications: deliberately tagging you in images in which you don't appear.

In this latest scam, which borrows a long-running prurient Facebook meme about 'Girl must be out of her mind,' you appear to be tagged in a pornographic, or at least semi-pornographic, movie, which is then recommended to your friends.

Of course, this raises two questions about Facebook's facial recognition. Firstly, now it's universally enabled, why does it allow you to be tagged in photos in which you obviously don't appear? (The April scam I linked to above tagged you in photos of food which contained nothing even vaguely resembling a human face.)

Secondly, is it really acceptable to allow tagging without the permission of the taggee? Back in March, we wrote about a judgment in the Kentucky courts which decided that the law does not require the taggee to be asked. But is that a good enough standard for Facebook to follow?

Facebook will notify you when a friend tags you, but I'd love to see that changed to a stricter default. You should be notified and be asked to approve the tag before it is accepted by the system.

Lastly - and this shouldn't really need saying, but I shall say it anyway- DON'T APPROVE FACEBOOK APPS, TAKE SURVEYS, OR PROACTIVELY LIKE ANYTHING in return for access to a video.

If you really must see for yourself whether This Girls Must Be Watch Out Of Her mind After Making This Video, why don't you just search for it on YouTube, thus sidestepping the Facebook scammers entirely?

Or learn a touch of restraint, because it goes a long way towards improving your security online. In short, THINK BEFORE YOU CLICK.

Keep abreast of the latest Facebook security threats by joining the 100,000 strong community up on the Sophos Facebook page.

Follow @duckblog

-

PS. My apologies for SHOUTING above. But we ought to know better by now!




"