Finding vulnerable Twitter accounts with expired domains

https://zainamro.com/hacks/finding-vulnerable-twitter-accounts

by zainamro • 6 years ago

196 125 6 years ago

What would be a universal solution to this problem? The only thing I can really think of is platforms not allowing custom domains for connected email accounts, but that seems sub-optimal.

sjroot• 6 years ago

If you deliver email to a customer and you notice that it bounces, any account security flows requiring access to that email should be disabled. Additionally, you should never show the full email address or phone number that is being used for an auth challenge. Nonetheless, those defenses will eventually be compromised.

Beyond that, it is not a company problem IMO. One of the most common uses for custom domains is custom email addresses. If a website prevented me from using it, as you propose, I would be flabbergasted.

cortesoft6• 6 years ago

I think you underestimate how often there are intermittent mail delivery failures, especially for custom domains.

krly• 6 years ago

On the user-side, using private email relays (i.e. Apple's Hide My Email, AnonAddy, etc) mostly eliminates this issue.

est312• 6 years ago

cronjob to regularly check if the domain is expired/up for sale? The service "has this domain changed owners in a way it's relevant for logins" could even be turned into a SAAS startup... later to be extended to individual accounts (someone deletes e-mail acct, cancels phone plan, etc. then a new person creates a new one with just that name) One could strike contracts with all the e-mail providers and phone networks to tell via API when this happens and then send the info to services that use those accounts.

JoshTriplett• 6 years ago

What would you do in this situation though? People still need to be able to reset their own passwords. And some accounts don't have any other means of contact. It's extremely common to only have an email address and a password.

komali2• 6 years ago

What does "custom domain for connected email accounts" mean? Isn't every domain custom? Do you mean anything that isn't @gmail.com?

rickdeveloper2• 6 years ago

Yes, roughly speaking any domain you registered yourself.

pazu• 6 years ago

Instead of blocking custom domain email addresses outright, the site could require a secondary recovery email address from an approved provider when an email with a custom domain is used to create the account. Then any security interaction like password reset, or 2fa would go to the primary address and would send an alert to the secondary email address about the nature of the communication. There could be a link in the email (sent to the secondary email address) that could allow the user access to instantly lock the account and/or disable access to the account from the primary email address until the user updates thier settings. The secondary recovery email address should not be able to be changed without an email confirmation (to the secondary email).

Good practice for users in general is to use email services like gmail as thier login/account email and add thier custom domain emails in thier bio.

leonidasv2• 6 years ago

But what if the provider takes your account down? You end up with an unrecoverable account.

techsupporter• 6 years ago

Instead of blocking custom domain email addresses outright, the site could require a secondary recovery email address from an approved provider when an email with a custom domain is used to create the account.

Great, if we do this, we've done to e-mail addresses (and domains) what we've done to phone numbers. Some phone numbers, because of the carrier serving them, are "less than" others out of some (mistaken) idea that it's easier to get a bulk-load of phone numbers from some kinds of carriers and not others.

And then, what do you do when a new provider wants to join the scene? It already takes a year of process and documentation for a new certificate authority to get into most browsers and even then the adoption will be years in the making because most devices don't get root certificate updates. What's the process like for e-mail in your hypothetical? Does Hey.com not even bother because getting buy-off from even the top 50 account-based web sites takes forever?

Good practice for users in general is to use email services like gmail as thier login/account email and add thier custom domain emails in thier bio.

Absolutely not. The entire point for using my own domain is so my identity is not irrevocably tied to Google. When Google can, and does, nuke my account from orbit on a whim due to some perceived slight, I have no recourse. I can't even sue because of the mandatory arbitration clause they slapped in their several-thousand-word terms of service.

Lammy3• 6 years ago

Instead of blocking custom domain email addresses outright, the site could require a secondary recovery email address from an approved provider when an email with a custom domain is used to create the account.

No thank you, I don't want a mandatory backdoor for every government that might want to claim jurisdiction over one of those large worldwide providers.

zhte415• 6 years ago

the site could require a secondary recovery email address from an approved provider

No. I have a domain precisely because of avoiding a monopoly, duoplily, oligopoly on my email. Any service that required this would have me walk. The footsteps of a single zhte415 may not be loud, but I feel, especially in tech, I would not be alone.

acid__• 6 years ago

2FA that can't be bypassed with a password reset?

WA• 6 years ago

This was a common way to harvest 6-digit ICQ numbers back in the day. Hotmail, MSN etc. had expiring email addresses as well that you could register to reset the password to the ICQ number.

vmception3• 6 years ago

oh yeaahh I forgot about the travesty of expiring emails on free services.

ObsoleteNerd2• 6 years ago

Yeah this has been a common attack since as early as I can remember. Company goes bust? Wait for their domain to expire then register/catch-all and start seeing what mail you get from websites to see where there’s accounts using that domain. Also plenty of more targeted methods too.

Thorrez4• 6 years ago

I wonder if it would be useful to use Have I Been Pwned to find a list of accounts on websites using that domain.

vmception3• 6 years ago

This attack can potentially be executed on other platforms besides Twitter, assuming one can find a similar discovery method

You don’t need another discovery method after you take their Twitter account and email :)

Only for targets not on twitter.

My point is that Twitter is probably enough.

But if you really just want to compare domain names that are expiring to email addresses, you can just use one of those business bots that spammers, recruiters and sales people use, and just check emails in their database to domains expiring.

superasn2• 6 years ago

Even though they show the starred email address and one of the suggestions is not to show the email, I really hope people don't do that.

There is nothing more frustrating when you're recovering your password and the site says we have sent you an email with no hint where and even worse sometimes they say "if that email was in our records then you should get the link" and you're wondering did that work and #1 worst is after making me solve 10 traffic lights and zebra crossings.

Because at that moment I feel it's just easier to start over and create a new account.

ugexe3• 6 years ago

I don’t think you having to either A) remember what email you used or B) creating a new account is a big ask when the alternative is leaking your account presence on a given system. Not everyone wants other people to be able to essentially query a given app for an email account.

reaperducer2• 6 years ago

The vast majority of people don't use the same e-mail address for their entire lives.

popotamonga• 6 years ago

Amazon leaks iirc

marcosdumay• 6 years ago

Oh, much better is the "you tell us what email you told us" approach.

capableweb• 6 years ago

I understand you feel that way, just want to explain why sites do that. If they give you a clear answer yes or no if it worked, others could check which emails are registered on the website. So in order to leak the information on who has an account or not, they are ambiguous with their answers if the recovery was triggered or not.

It's, as always, about a balance between faster user experience and more extensive security features.

Taek2• 6 years ago

At some point in time we decided that email addresses control the keys to the kingdom. If you lose access to your email, there goes your social media accounts, your bank accounts, your gaming accounts, and potentially many of your commercial accounts as well.

And then we decided that custom domains are the most professional. Which does make sense, there can only be one 'robert@gmail.com'. But, this is coupled with the idea that domains can expire, and that expiry does not appear to kill the identity that's potentially associated with the domain.

We should not be using email addresses as our primary source of identity verification in the first place. And we definitely _should_ have some way to globally declare that an identity has been compromised. Especially given our society's track record of keeping database safe from breach.

I more or less assume it is inevitable that one of my major accounts will be compromised, and that this will be able to cascade into most of my major accounts being compromised. I do what I can to protect myself, but gmail as a single source of failure makes me nervous. Using any email provider besides gmail makes me even more nervous, because they don't have the full power and knowledge of Google protecting their databases.

asciident• 6 years ago

You point out some problems, but how do we actually do these?

Without emails as the keys to the kingdom, what would you use?

Without a global identifier for a human person (like social security in the US), how would we declare that an identity is compromised?

While I believe your ideals are well-intentioned, I think they're impractical in our current society.

I would propose that an email is the key to the kingdom, that people running custom domains and use them for email must deposit $500 in registration to do so (to ensure the domain is registered for their lifetime), and that they should be protected by a password plus 2FA with your phone being the other factor. And I propose that each person should be uniquely identifiable by an email address stored in a global publicly-accessible database.

dewey2• 6 years ago

There's a difference between an email address and a social security number in a way that the latter will still be around if you stop paying for it or something happens to you. In some way (at least for this threat model) a gmail address is better than one on your own domain as it's unlikely to go away or get taken over.

wutwutwutwut2• 6 years ago

This is a solved problem in many other countries. Instead of proposing some new solution maybe it would be better to copy an existing which has already proven to work.

Taek2• 6 years ago

I would suggest having a bank or similarly regulated institution manage identity recovery. They can declare a login invalid, and they can go through the process of KYC (drivers license, SSN, in-person visit, etc) to get you a new identity.

Think Facebook login except instead of tab unrestricted entity that steals every piece of dignity it gets its hands on, its a bank or legal custodian with strict responsibilities, penalties, and insurance in case of identity theft.

rexpop2• 6 years ago

Without emails as the keys to the kingdom, what would you use?

From Ursula K. LeGuin's indispensable "Dispossessed":

“You're really much too polite for ...”

“For what?”

“For an anarchist,” she said, in her thin and affectedly drawling voice (it was the same intonation Pae used, and Oiie when he was at the University). “I'm disappointed. I thought you'd be dangerous and uncouth.”

“I am.”

She glanced up at him sidelong. She wore a scarlet shawl tied over her head; her eyes looked black and bright against the vivid color and the whiteness of snow all around.

“But here you are tamely walking me to the station, Dr. Shevek.”

“Shevek,” he said mildly. “No `doctor.'”

“Is that your whole name — first and last?”

He nodded, smiling. He felt well and vigorous, pleased by the bright air, the warmth of the well-made coat he wore, the prettiness of the woman beside him. No worries or heavy thoughts had hold on him today.

“Is it true that you get your names from a computer?”

“Yes.”

“How dreary, to be named by a machine!”

“Why dreary?”

“It's so mechanical, so impersonal.”

“But what is more personal than a name no other living person bears?”

“No one else? You're the only Shevek?”

“While I live. There were others, before me.”

“Relatives, you mean?”

“We don't count relatives much; we are all relatives, you see. I don't know who they were, except for one, in the early years of the Settlement. She designed a kind of bearing they use in heavy machines, they still call it a `shevek.'” He smiled again, more broadly. “There is a good immortality!”

Vea shook her head. “Good Lord!” she said. “How do you tell men from women?”

“Well, we have discovered methods...”

...

The five- and six-letter names issued by the central registry computer, being unique to each living individual, took the place of the numbers which a computer-using society must otherwise attach to its members. An Anarresti needed no identification but his name. The name therefore, was felt to be an important part of the self, though one no more chose it than one's nose or height.

pwdisswordfish0• 6 years ago

Without emails as the keys to the kingdom, what would you use?

PKI. Service providers shouldn't give you access to an account just because you can prove you control an email address (during a narrow and predictable time window, no less). The simplest thing would be to encrypt the relevant part of the payload (the one containing the password reset link), so resets are only possible if you can receive the email and have the means of reading it in its "true" form.

Failing that (suppose you've not just lost your password but also the ability to decrypt the contents of the message), there should be an alternative, but the threshold for proving your identity should increase. It would ameliorate a lot if it meant that people had to show up in person somewhere. E.g., I show up at either the business's local branch (if there is one) or the USPS (or...) with my photo ID. From there, an attestation is generated that you really are who you say you are, and only with that attestation will your account be unlocked.

twicetwice4• 6 years ago

I want a private key embedded in a chip, that never leaves that chip, so all encryption and decryption happens on that chip—similar to how chip-and-pin credit cards work now. I'm identified by the corresponding public key. Then I want to embed that chip in my hand. Then I can unlock my car, house, computer, or phone and sign into any online service the same way: you send me a challenge token, I sign it with my private key then send it back.

hirsin• 6 years ago

CAEP provides this to some extent https://openid.net/wg/sse/ - but now you're asking for a whole bunch of systems to be able to talk about you in back channels which other people will find fault with.

paulpauper4• 6 years ago

2FA works well in many instances if your email gets hacked

chrismarlow9• 6 years ago

At minimum register a domain and email forward the wildcard address for it to your daily driver. Use this for important things and don't forget to renew.

Edit: you can do all this on namecheap pretty easily.

widforss• 6 years ago

"assume that a public key cryptosystem exists"

anoncow2• 6 years ago

Some organisation will try to own it and then users will be at the risk of getting banned and losing themselves.

anoncow2• 6 years ago

There are other aspects here.

If you use a third party service for your email ID, the third party can ban you or like you mention - disappear and basically take your identity away.

If you rely on national ID cards, you have another set of problems.

If you rely on phone numbers, these can be sim-jacked.

If you rely on bio-authentication methods, you risk your privacy especially when the master database gets compromised.

Relying on any single source seems to be a recipe for disaster. Perhaps the solution is to have multiple ways to authenticate yourself, with different levels of credibility and to let as many of them survive as possible. Phone numbers and email IDs seem to have similar levels of credibility, but I haven't seen domain name service providers take to phone number authentication as much as I would have liked, but things are looking up. Alternatives could be backup codes, which some registrar's use if you have 2fa enabled.

jmull3n• 6 years ago

If you rely on bio-authentication methods, you risk your privacy especially when the master database gets compromised.

It's my understanding that these methods (TouchID, FaceID) don't actually store your thumb prints or images of your face rather they store hashes of the output. Similar to how passwords should never be stored in plain text.

cortesoft6• 6 years ago

The problem is that every new source of identity added is another new attack vector. If there are 10 different ways for me to prove I am who I say I am, it only takes a security flaw in one for my account to be compromised.

hnick3• 6 years ago

I think the usual suggestion is a public/private keypair. You then sign accounts saying they are yours.

This would also allow you to have multiple identities in cases where that is useful.

I've heard of various groups doing this under blockchain (of course) which is a way to solve the problem of publishing the details, but in many cases you don't really need that. It should be enough to make a key and get involved, like Bitcoin.

The issue of course is that if you lose the key(s) you have a major problem, whether they're just lost or stolen. This is probably solved with MFA but it's not a solution if that opens up other attacks.

young_unixer• 6 years ago

For me, email has much more credibility than phone numbers.

The email market has worldwide competition, phone providers compete at a local level only. You can choose from thousands of different email providers, while phone provider choices for any given person are ~5.

The effective 'god' of domain names is IANA, which, while imperfect is more trustworthy than the 'gods' of phone numbers: local governments and telcos.

notatoad• 6 years ago

Gmail is only a single failure point if you let it be one though - set up 2fa on all your accounts, and this problem is solved.

ObsoleteNerd2• 6 years ago

Google bans/locks/deletes accounts for arbitrary reasons all the time, with absolutely zero recourse for the user.

jb7752• 6 years ago

We should be using biometric markers filtered through homomorphic encryption.

This way we can verify/prove our identity without handing over those markers to multiple 3rd parties.

varenc• 6 years ago

Biometrics are unrevokable. If yours are compromised through some other way then you can’t trust biometric authentication for the rest of your life.

giancarlostoro• 6 years ago

Maybe there should be some transparent way for mail servers to request public encrypted keys to an email address and any incoming mail gets decrypted by the private key. So if someone hijacks your domain any password reset emails should be gibberish unless they magically got the private key, in which case you have worse problems.

This is the only technique I think might work till someone social engineers people at Twitter.

joedevon• 6 years ago

Indeed. What if you are a super responsible person, but there is unrest in a Country you are visiting or live in, through no fault of your own and you are unable to pay a renewal. Or you fall sick and go to the hospital.

jcims• 6 years ago

Curious what Twitter would do if this was contested later.

mobilio• 6 years ago

If you get domain you can watch for mails from LinkedIn, Pinterest, Facebook, Instagram and many more!

ErikAugust• 6 years ago

Anyone else have people sign up for accounts with your email address? I had one recently where I could access a working GrubHub account for a while. And in the spirit of lame on-boarding optimization and “churn” prevention, while I could have used it - I couldn’t cancel the account. That required the phone number associated.

iotku• 6 years ago

I had someone create a spotify account on one of my emails with an old (clearly burnt) password as the the username.

Why? I figure that's generally either for spamming or viewbotting (Re: likes, stars, etc) purposes especially on sites that don't require email verification to do things.

arkitaip• 6 years ago

Only every other day. Most I don't care about but the major social networks? Yeah, I'm closing those accounts down ASAP because of the id theft risk and what not.

Lammy3• 6 years ago

On the plus side, it's heartening to learn enough people use non-GMail/Outlook/Yahoo/WhateverSilo email addresses to make such an attack viable :)

blindm• 6 years ago

One has to wonder about sustaining access to a compromised account. Twitter in my experience has been very aggressive in asking to verify my account with a phone number when logging in from shady locations / with a VPN. What if you get access to an account using the method described in the article, but then days later get locked out due to suspicious-looking behavior / you don't have access to the phone number used to register the account?

paulpauper4• 6 years ago

you would remove the phone number after logging in. if it asks for the phone when longing in initially , then you are SOL. to prevent this, the hacker would make sure the location of the account matches the country of the IP longing in.

paulpauper4• 6 years ago

i dunno how this got to the front page. this is an extremely old vector and not even that effective given the tiny, tiny likelihood of finding a domain or account that works., It would actually be cheaper to buy an old twitter account from someone who does not his account anymore legit, than try to go through millions of accounts, which requires tons of proxies and other evasion methods. Twitter is not easily searchable and neither is google. Twitter has extreme rate-limiting measures, so you need a lot of proxies for this to work and those cost money.

jl6• 6 years ago

This isn’t the workflow I see when trying the password reset process on an old account that I’ve recently tried to recover. I’ve forgotten both the password and the email address associated with the account, but I know the domain I would have used, and I own it so I could easily prove ownership of the email address if I knew what it was.

But when I click Forgot Password, it asks me for my username and also the email address before I can continue.

How do you get the email address hint like the article shows?

stevenringo• 6 years ago

I am also not seeing the behaviour that the OP describes.

thdc• 6 years ago

What if we could have services encrypt their emails sent to us via pgp? eg Twitter (or anything else) asks for your public key and then sends all future emails using it.

giomasce• 6 years ago

Facebook does that if you add your key to your account.

megous• 6 years ago

Perfect! A true second factor. Not just some annoying gimmick, like SMS.

bdcravens• 6 years ago

My wife and I started up a small reselling business, based on our name. The dotcom for it was previously owned, but they let the domain lapse, but they still have the Twitter account (that has the web address we now own in their profile; they haven't posted since 2016). I tried an approach similar to the article, but they apparently used Gmail to set it up. (I reached out to them to buy it to no response; I assume that Twitter account has been orphaned)

vmception3• 6 years ago

time to add an underscore to the name

Lammy3• 6 years ago

Or maybe see if they Have Been Pwned in the past.

jimmies• 6 years ago

This domain hijacking idea reminds me of an incident with Google I discovered a couple of years ago that landed me a bug bounty with them. I found out they created email logins with a not-registered domain for their candidacy account. I ended up registering that domain and "sold" it back to them in good faith. At least I can die with a smile on my face -- I once sold Google a domain.

details: http://www.tnhh.net/posts/gcandidate-who-is-interviewing-wit...

TwoBit• 6 years ago

Did you get the job you were looking for?

Thorrez4• 6 years ago

I believe it accounts for a large portion of stolen accounts/handles on the platform.

I doubt it's a large portion. It costs money for each hijacked account, and custom domains I would assume are only used on a tiny fraction of accounts. The vast majority of stolen accounts I would attribute to credential stuffing.

tucif• 6 years ago

I've thought about this in terms of people passing away and the domain no longer being renewed afterwards.

10 years limit on domain registrations seems ridiculous, we need lifetime-span registration capabilities, at least.

rootsudo• 6 years ago

This has been standing practice for a while and is not connected to just Twitter. Sometimes you can find public NDR's online via bug reports and such and easily grab a service account.

palad1n• 6 years ago

Heh. I did something like that: https://xach.livejournal.com/227751.html

homero• 6 years ago

Didn't Yahoo close unused accounts at some point opening the doors to all kinds of takeovers?

SR-71_Blackbird• 6 years ago

Old news, this has been known for years.

Fnoord• 6 years ago

This is how I used to get all kind of old ICQ numbers back in the 90s. Hotmail addresses, back then, used to expire.

Ironically enough, I've been vulnerable to the described attack afterwards as I had my own domain, didn't use it much anymore, and gave it away (to a band with the same nickname). Back then, a domain was pricey, and I was poor, so...

Finding vulnerable Twitter accounts with expired domains

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