How to find phone number of facebook friend
Revelations last year that Facebook was using personal data obtained for two-factor authentication to serve advertisements enraged privacy advocates, who called the practice deceptive and said it eroded trust in an essential digital security tool. It had already stopped allowing those phone numbers to be used for advertising purposes in June, the company said, and is now beginning to extend that separation to friend suggestions. Federal Trade Commission, which required it to boost safeguards on user data to resolve a government probe into its privacy practices. The FTC order, which is still pending approval in court, said Facebook failed to disclose that the phone numbers provided for two-factor authentication also would be used for advertising, and specifically barred that approach to security tools. The change - which is happening in Ecuador, Ethiopia, Pakistan, Libya and Cambodia this week and will be introduced globally early next year - will prevent any phone numbers provided during sign-up for two-factor authentication from being used to make friend suggestions. Existing users of the tool will not be affected, but can de-link their two-factor authentication numbers from the friend suggestion feature by deleting them and adding them again.
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Facebook really wants your phone number, nagging you for one as soon as you join. This isn't all bad since it can help secure your account with two-factor authentication.
On the flipside, this makes it easy to reveal the private phone numbers of virtually anyone on Facebook, including celebrities and politicians. We're going to look at how a hacker would do this and how to protect yourself. Many Facebook users may not even realize that their private phone number is connected to their Facebook account, having forgotten that they did so. Facebook isn't allowed to simply extract your number from your phone, but they can do what I refer to as the "app equivalent of cyberbullying" by repeatedly asking you to confirm and save your number each time you launch Facebook.
The default privacy setting on Facebook allows anyone to search for you by your phone number once you add it. This is not a new issue. It has been around as long as the Facebook Graph search, but Facebook chooses to see this issue as a feature, as a letter received by Belgian researcher Inti De Ceukelaire shows. Certainly, some people, such as celebrities and politicians, should be more concerned than others about revealing their private number online. However, anyone could potentially have a cyberstalker or hacker target them.
Once a hacker has a phone number and your name, they can quickly use open-source intelligence OSINT tools that we've covered on Null Byte to grab further public data like occupation, employer, spouse, relationship, any other public info. A hacker could use the information to further social-engineering attacks by calling you directly. Think of the classic " Microsoft tech support" scam, only the caller trying to trick you knows your name and intimate details of your personal life.
Armed with these, it's easy to make the target think the caller is legitimate. How would a hacker actually go about finding your number? In theory, if they had a lot of time, they could just search all 9,,, potential numbers until they stumbled upon yours.
Clearly, this isn't very efficient, so let's see the right way of doing it. In the examples below, her number was changed to protect her real number. If you think of a target's phone number as one of all the possible digit US phone numbers, you can quickly see that 10 billion North American phone numbers it far too large a list to effectively search through. Let's take an example: Looking at the NANP, we can see that the first three numbers are the area code, and the plan allows for 2—9 as the first digit and for the second and third digits.
That information right there eliminates one billion possible numbers from the hacker's list. The hacker can also quickly take advantage of this if they know or can take an educated guess at where you live, as it's as easy a Google search. By doing this, the hacker can remove a further 9 billion million numbers from the list of potential guesses. The next three numbers after the area code in our example are the central office prefix.
Again, the plan calls for 2—9 for the first digit and 0—9 for both the second and third digits, but with a caveat. In area codes where the second digit is 1, the third can't also be 1. This yet again removes a large number of phone numbers from the hacker's list. The last four digits of the phone number is the line number, in this case, I took the educated guess that the Mayor of DC would have a DC area code, and a hacker could also look up the target's Facebook account and likely find a hometown or the current city the target lives in or works from.
Some larger cities like Los Angeles will have multiple area codes within them, but no matter how many "split" area codes there are, it still greatly reduces the hacker's list of possible numbers. Now that I know my target's number is ??? Thankfully, Facebook has our back and has made this probably the second easiest step, after using the area code. In order to get the last two numbers, we just have to go a few steps into the password reset process.
To do this, the hacker goes to the main Facebook page and clicks "Forgot account" to start the process. The hacker is then presented with a list that includes a face picture paired with each matching account that helps them quickly identify their target.
There's our target right at the top! Facebook then kindly provides the hacker the last two digits of the targets number, along with some information about the emails accounts associated with their Facebook account, such as the first and last letter, and sometimes the email domain. That's as far as the hacker has to go. They don't actually reset the password, and they shouldn't so that the target never receives any kind of notification to tip them off. With over million users, PayPal and other services can help add to the information the attacker has collected so far.
In this case, if the target is a PayPal user, the hacker can get two additional digits of the phone number we're looking for. In the picture above, you may have noticed that the first email listed is a Gmail account that starts with "M" and ends with "R. That's funny, since my targets first name starts with an "M," and her last name ends with an "R. Google accepted it, but that doesn't necessarily mean that it's the target's email. The hacker can check by doing the same password reset trick they pulled with Facebook.
Yep, this account just so happens to have a number that ends in I think not. Now that I have an email to work with, I can jump over to PayPal in a new tab, and once again, use the same password reset trick. This time, when I get to the password reset screen, I get not only all four digits of the line number, but also the first number of the area code too!
This allows me to be reasonably sure that I'm on the right track with the area code, and verifies my previous work on finding the last few numbers. This means I have the number ??? In other words, my list has gone from 10 billion choices to about a thousand in just a few minutes of work. At this point, a hacker could just start throwing numbers into the Facebook search bar, but that still wouldn't be that efficient.
So what does a lazy hacker do? They take advantage of a Facebook feature that allows you to conduct a bracket search. Facebook allows you to upload lists of contacts in CSV format, and then tells you if they are on Facebook so you can add them as friends.
By constructing my own contact list of potential numbers, I can quickly rule out large chunks of wrong numbers. In this case, I know the number has to be in the range from to By cutting that in half and creating a list of numbers from to , I can effectively rule out half of my list, as the target will only be in one of the two half lists created.
Then, I can upload the list and instantly determine if they are on it or not. From there, a hacker can open the file in Google Sheets or Excel and change the column formula for the phone numbers to one that will iterate over the numbers they need to check, as seen in the following example.
In the excel formula below, I start by taking the lowest value phone number, in this case, , then I add 10, to it in order to increase the fifth place digit by 1. This formula will repeat as many times as needed, but we shouldn't do it more than 1, times because there are only a thousand numbers in our list to guess.
If the target hadn't had a PayPal account to help us derive the third and fourth place digit, then we would be adding to increase the third digit instead. From there, it is simple to sign into a Facebook account and go to the Friend Finder feature. Click on the Gmail logo and then "Find Friends.
Next, scroll to the bottom of the page and upload your CSV file containing the phone numbers you wish to try. After it's uploaded, Facebook presents the hacker a list of "Friends" to add from the list. They would then search for their target inside that list.
My target doesn't seem to be here, so I know they aren't in this half of our batch of numbers. Next, instead of testing the next , I split the next in half and check one of those halves. This is because I already know the target will be on the second list since they weren't in the first half. The hacker can continue searching in this way until the target appears on a phone number list. From there on out, the hacker would test smaller and smaller batches of numbers until they have only a handful to test.
I stopped when I had it down to about 30 numbers. Obviously, this will take longer if the hacker has less information about the other digits of the phone number to begin with, as they will have a larger number set to search. Facebook will rate-limit the hacker to five attempts per day but they can get around this by signing into another account.
Once that hacker has it down to a handful of numbers, they can go to the Facebook search bar and type them in one by one.
To do so, just type the number into the search bar with no hyphens. In total, it took me around 30 minutes to an hour to find the target's number, and these same steps could be used on anyone who has their phone connected to Facebook. The simplest way to protect yourself is to never connect your phone to Facebook. If you still want to use two-factor authentication, Facebook allows you to use a USB U2F device without having to rely on your phone.
If you absolutely must have your phone connected, navigate to Facebook Settings , select "Privacy," then "Who can look you up using the phone number you provided?
On a mobile device, you would tap on the three-line menu icon, select "Account Settings" iOS users will have to select "Settings" first , then tap on "Privacy. While this still will not provide absolute protection, it will make the hacker's life much more difficult. Thanks for reading! Want to start making money as a white hat hacker? This is an amazing article.
I do have one addition. Then grep out everything that is wireless and you have all the wireless possible numbers in DC on a single list. This will be a much faster way at discovering the number.
Thanks for the tip Jimothy, I was thinking of something along those lines but didn't ever getting around to testing it. There is one potential problem with greping out the wireless central office prefixs, the categorization on that site seems to not be super accurate as the target's number falls on a landline prefix. Keep in mind that anyone can transfer a landline number to a cell phone or vice versa and that has likely muddied the waters over the years.
That being said I think what you propose is a good plan to quickly cut down the list of numbers if you're willing to accept the small risk that the target will be excluded. Hi, i have got a problem: when I try to upload my contacts to facebook it appears a "message" saying that my contacts have got to include an e-mail.
Does anybody know how can I fix that please?
How to find someone on Instagram using phone number
Facebook really wants your phone number, nagging you for one as soon as you join. This isn't all bad since it can help secure your account with two-factor authentication. On the flipside, this makes it easy to reveal the private phone numbers of virtually anyone on Facebook, including celebrities and politicians.
Join , subscribers and get a daily digest of news, geek trivia, and our feature articles. Well, then it becomes a lot tougher. This kind of information is generally kept private and is closely guarded. If you really need to call someone, you may be stuck asking for their phone number directly.
How to Search for People in Your Contacts on Facebook Using Your iPhone
Searching Facebook is a great way to find someone online. With it being the largest social networking site in existence, your odds of finding the person you're looking for is fairly high. Facebook lets its users add lots of information about themselves to their profile, and the inherent function of the site is to bring people closer together through information sharing. You can leverage this to help you find someone on Facebook, whether it's a friend you used to know, an old coworker, neighbors, family, etc. Facebook isn't the only way to find someone on the internet. The main search bar at the top of the website is one method for finding people on Facebook by their name. You can type the person's name and then filter the results to narrow them down. Don't know the person's name? You can still do a Facebook search for someone even if you're not sure what their name is.
How to Check for Phone Numbers in Facebook
Jump to navigation. All of you must be aware of the fact that we can find friends on Instagram through search bar by just typing their username. But, what if you don't know the person's username? Many of us don't know that Instagram also allows us to search our friends even if we don't know their usernames through the medium of phone number.
Facebook is the default social networking solution for personal as well as business marketing. Even major corporations such as financial institutions and auto parts stores are using Facebook as a key marketing tool. To make the best use of Facebook for your business, you must connect with a wide network of people. Using the Facebook application for the iPhone, you can use the application's "Find Friends" feature to access your iPhone contact list and it will search Facebook so you can send out friend requests to your contacts.
How to Get an ID & Phone Number From a Facebook Link
If you know someone's phone number, you may be able to use it to find someone's Facebook account. As long as the phone number is associated with an account, the account will come up when you search for the phone number. This wikiHow will show you how to search a phone number on Facebook using the website or phone app. Click the search bar. Type phone number and press Enter. Click search result.
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