Yahoo discloses hack of 1B accounts
yahoo.tumblr.com
yahoo.tumblr.com
It does, however, _happily_ accept `passwordpassword` and cheerily move along to confirming that my recovery email account from 2003 is still valid.
Not that it's much better. Is it so hard to allow 50 character passwords?
In the interests of hewing closest to cryptographic reality, I design not to allow a password longer than the algorithm can usefully use.
To upload 100s or even more than a few megs you need a multipart message, a password form won't accept MP http requests.
I say "seemed" as I did not go through the exercise of testing with multiple combinations of name, initial, and password.
Time to update that article from September. Hooray for Yahoo, they made it 76 days without a 500M+ user security breach.
(No, I don't know the actual dates... just making a joke.)
Strong passwords that need to be memorized shouldn't be wasted on security bozos
> hashed passwords (using MD5)
I don't even know what to say.
> investigating the creation of forged cookies that could allow an intruder to access users' accounts without a password. Based on the ongoing investigation, we believe an unauthorized third party accessed our proprietary code to learn how to forge cookies
How is this possible? Aren't most auth cookies just a session ID that can be used to look up a server-side session? Did they not use random, unpredictable, non-sequential session IDs?
2) Yahoo doesn't use a centralized session storage. If you know a few values (not disclosing the exact ones) from the UDB, it's theoretically (guess not so theoretical now) possible to create forged cookies if you steal the signing keys. To my knowledge, the keys were supposed to only be on edit/login boxes (but it's been a while so I may be forgetting something), so this is a pretty big breach.
In both cases I tried to track down backups, but discovered neither company was keeping them. That is another possible vector.
2) there's no SQL database involved with Yahoo!'s storage of passwords. It's a custom built db system with proprietary access and replication protocols.
The NSA's MUSCULAR program for example decoded proprietary secret squirrel cross datacenter replication protocols designed by both Google and Yahoo, so that isn't much of a safe guard against state level actors.
Wouldn't the upgrade require the accounts to actually login to migrate password? Last I was at Yahoo there was at least 3B junk accounts in UDB. With out knowing details I am guessing that many of the "compromised" accounts fall into that bucket.
I get that membership can't just trash junk accounts but marketing was very aware of them. Paranoids also can't just say a compromised junk account is not a compromise, they are too paranoid for that.
This unfortunately sounds bad PR wise, with little knowledge of actual impact. On the flip side I'm pretty sure I am not on the radar of the state actor since they would more then likely be looking at their own.
As to your question, no, they didn't need to login due to how the hash "upgrade" was done (unlike how Tumblr did it around the same time). I was one of the people in the billion accounts and I definitely have logged in and also changed my password multiple times (also have very high entropy passwords and use TFA).
Tumblr was indeed what I was thinking about.
Although...he IS cool.
The correct response is force a password reset, and _delete_ weak hashes so that they cannot be stolen in a subsequent breach. At worst, store a bcrypted md5 password as you suggest, but only as a check for a password the user must not be allowed to use again; it _cannot_ be used to sign them in.
One of the attacks you're preventing is on _other_ sites, where the user has reused the passwords. Keeping around weak hashes even to let that user perform a reset is risking that hash being taken, cracked and used in a breach elsewhere.
[1] (EDIT: now with screenshots) http://imgur.com/a/g61VZ
[2] (Not affiliated with link, but the risk-averse may wish to open in a sandbox) ftp://hackbbs.org/milworm/270
If these accounts are not deleted (and there are a bunch of organisational reasons not to), then the MD5 hash has to be kept around somewhere, until the user re-enters a password and a better hash is generated.
Isn't that highly confidential company information?
You check the plaintext password sent to the backend against the md5, on success you rehash it as bcrypt, insert it in the table.
To prove me wrong you can try and reverse this one (unsalted , just one round):
27c8ac15df9357d92385f59aea2049e0
> "[...] we may allow other users to sign up for and use your current Yahoo! ID and profile names after your account has been deleted"
Bummer if you forget that it was the password reset email for your Facebook account, huh? Instead of deleting your account, purge it of all data: https://honeypot.net/purge-your-yahoo-account/
So that exactly explains how my Yahoo account was used to send spam despite having a password that can't be reasonably brute forced (despite them using MD5). :-/
Most likely either: 1) you were phished and didn't realize it 2) logged in to your Yahoo account from a device that had malware on it
Or stealing $6,000 with $100,000 gun :)
http://www.fenrir.com/free_stuff/columns/callcops/ctc-436.ht...
Regardless, it was some sort of automated spam/phishing emails that were sent from Yahoo's network using my account to contacts on my list. I analyzed the headers of multiple bounced messages that were sent to email addresses no longer in use and confirmed the origin of the traffic.
I'm not going to fall for a phishing attack and I only access email from devices I personally control. Could one of them had some sort of malware infection? I guess it is possible but I am security conscious and it is highly unlikely. I also would expect a hacker that has compromised one of my devices would be far more interested in using my banking credentials than using my Yahoo account to send spam.
EDIT: To clarify, I mean specifically with md5. I'm by no means an expert, just curious because I had considered md5 so broken that this comment caught my attention.
MD5's weakness is that it's (relatively) easy to produce two strings which have the same hash. However, given an MD5 hash, it's not easy to produce a string which also has that hash.
In principle, one could intentionally construct two passwords which have the same hash. It's hard to see how that could be exploited maliciously - any attacker knows both passwords to begin with. Even then, making colliding strings that would make acceptable passwords hasn't been done yet, AFAIK: the shortest colliding strings found so far are 64 bytes long and contain several unprintable characters.
OTOH, computers are fast enough now that brute-forcing MD5 is practical for short strings with a limited set of characters, which is what passwords tend to be. One should use algorithms like PBKDF2, scrypt, and bcrypt which can increase their complexity as the computation capacity of potential attackers increases. This isn't because of a particular weakness in MD5, though, and one should equally avoid storing passwords as SHA-512 hashes, say.
The thing you definitely shouldn't use MD5 for is digitally signing a file you didn't make, because it's possible that whoever did make it also made another file with the same MD5 hash, for which your signature would also be valid.
http://www.hackedpodcast.com/episode-3-the-problem-with-pass...
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More and more are migrating to cloud these days, I expect more and more epidemic leakage will come.
I host everything myself except for email, which is always a headache but contains more private info than all others I manage combined. Maybe it is time to run a small email server again but it is easily said than done, gosh please give me something like a working PGP or whatever for safe emails(PGP is dying from what I read)...
"The stolen user account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (using MD5) and, in some cases, encrypted or unencrypted security questions and answers. "
I'm a paid premium member for Yahoo's service for many years, I would like to join somebody else to sue the hell out of Yahoo.
If you can prove financial or other harm resulted from this, then yes, you'd might have a case.
Another avenue you could take is breach of contract or some similar claim. As in, you paid them and formed a contract according to their ToS, and their ToS (I assume) states they use at least reasonable security. Yet they didn't, which would be a breach of contract.
[edit] by the way I wonder how useful would be a tutorial "for dummies" of how to set up your own mail server from scratch. I assume that users who would be happy to pay for their own server but feel it is too complicated would likely be windows users, i.e. wouldn't mind having to pay for a license and would like to use an environment with a relatively exhaustive UI. I'll give it a try.
if you are looking for a perpetual license, grab the 46% discount that's going to end by 31/12/2016 from https://www.tweakservers.com/mail-servers/smartermail/
I have been doing both inbound and outbound for roughly 20 years on our own equipment. But even doing just inbound gives you better control and in a way you are able to lessen the attack surface of being a large vulnerable target.
~20,000 emails a day
Going on 4 years. AWS "blocks" are perfectly fine. If you are going to host your own just get your self an Elastic IP and let your account manager know that you intend to send mail. As they (use to? I had to do this 4 years ago) have their own internal anti-spam system which you may hit.
On the contrary I also host my own mail on an instance I have over at [0] which is rock solid and I've had no issues that are not the fault of my own. I would recommend at minimum.
The only thing I can say is if you want to do email yourself possibly use [1] for an easy to setup system and make sure you get a box with minimum 512mB of RAM or around 1GB because ClamAV is fat.
Or go [2] for a hosted solution. Who are doing great things regarding encrypted mail.
Why? Couldn't isn't relevant to security.
If anything, it makes it easier to configure firewalls and rights, so it's easier to put security in place.
I disagree. The larger the congregation of value by a single target, the higher value the target. Saying it doesn't impact security is like saying whether a building is a bank or a house doesn't impact security.
(It should also probably be noted that I assume the OP was referring to "cloud" as in centralized data services as opposed to "cloud" as in hosted servers/VMs)
Those security questions, on the other hand, are still fair targets.
So I ignored the hack a few months ago. I also never got notified that I was vulnerable.
Just now I tried to log in to see if my password had been invalidated. Nope. It was my old insecure "pattern-based" password (myprefixYAHOO) that I use nowhere any more. Probably short enough to have brute forced with MD5 in a few minutes at most.
And yet...no spam sent from my account. No spam in my account (except some kind of announcement from "Aabaco, the new name of Yahoo Small Business" from a year ago. Just some of the mail from the email list that petered out over two years ago as the list transitioned into a Meetup group.
So I guess Yahoo either has considerably more than 1B users, or there were simply so many compromised accounts that they didn't bother trying to use all of them to send spam.
Changed the password just now to something secure "just because", but it's hard to care.
1) their security isn't good just because of their scale/size (that begins to seem more and more like a false-assumption nowadays)
2) migrating your email to a new provider is quite difficult (consider that the average person will have just 1 - or 2 - email accounts and they link EVERYTHING to it)
3) the price of ads/convenience is no longer worth it. I'm assuming at least a sizable minority of internet users are using ad-blockers these days. They can't get your eyeballs, so they package and sell your data. Granted, you can probably now get the same (raw) data on the black market by paying a fraction in bitcoin and you'll get to see those billions of emails telling people someone attacked their farm in farmville from 2009
Lastly (and I really hope this happens), Yahoo implodes/collapses (cause the average Joe won't migrate willingly) and leaves a vacuum for their 500+ million email users. Hopefully the smaller providers (Proton, Migadu, Posteo, Tuta, etc.) get at least 10% of these users and the email-cartel is broken (somewhat).
I like Yahoo email as a user. Yes, they've made mistakes, and I accept that. I'd prefer their mistakes over Google's superiority complex.
GMail supports labels as folders. When you create a new label it will ask you if you want to nest the label under another label and you can do this repeatedly to make a nested folder structure.
Crucially, this will show up as nested folders via IMAP.
Their IMAP interface is both standards compliant and fully functional. I'm not terribly fond of the Gmail web/native apps either, so I just don't use them (though I do occasionally hop on the web app when my client isn't searching the email as effectively as google does).
With 2FA it can be a bit more work adding devices, but it's not a deal breaker for me.
Zoho needs a phone number verification for signup. Unless you're confident that Zoho will never get hacked like Yahoo has been (multiple times), your phone number could be one more piece of information that's exposed yet again whenever it gets hacked (this also depends on how you use email and if you include your phone number in emails).
http://penguindreams.org/blog/how-google-and-microsoft-made-...
I've also occasionally found really old services that use my old e-mail account. Even thought I have the password, they still require e-mail verification; which can't be done because the gmail account doesn't exist and it bounces.
Even if you pay for a host they still have access to it all. You have to really trust them.
If you try to set it up at home you need a static IP and need to be prepared for it never working because of spam filters and stuff not trusting dinky self hosted services.
And no matter what you do - barring PGP which nobody uses - it's all sent over plain text anyway.
But that's less worse than anyone having your entire email life with one hack. Sigh.
You do realize this makes you sound both terrible and ignorant, right? I happen to have a Yahoo account, which I registered way back when the options were that, Hotmail, and maybe AOL. I have self-hosted mail now, and a redirectable primary address, but that Yahoo address lives on in various address books.
If you want to realize your email dream, you should try to turn the Yahoo addresses into an eternal forwarding service for current accounts. Maybe you could sell space on the signup page to smaller providers.
""" Based on further analysis of this data by the forensic experts, we believe an unauthorized third party, in August 2013, stole data associated with more than one billion user accounts. We have not been able to identify the intrusion associated with this theft. We believe this incident is likely distinct from the incident we disclosed on September 22, 2016. """
this incident occurred in 2013 and 2016, or they needed three year to figure this hack out. How is this possible?
On the other hand, adding a price may embolden deep pocketed organizations to 'pay to absolve' for losing data to hackers on an ad hoc basis as a cheaper alternative to strong security and limiting data collection scope. In that case, the impotence of ID theft protection hurts a lot more.
I wanted to sign up for Flickr, but the Yahoo login requirement was a big turnoff, because it requires a phone number. This nagged me so much that I never did it.
Turns out: right decision. Because my 8 year old phone number isn't target of spam yet.
How the forensic experts could have analysed? based on the log data? my another question is, just assume if yahoo is trying to dump the experts, can it be possible? or else, still the experts be experts to make sense out of it?
"Separately, we previously disclosed that our outside forensic experts were investigating the creation of forged cookies that could allow an intruder to access users’ accounts without a password. Based on the ongoing investigation, we believe an unauthorized third party accessed our proprietary code to learn how to forge cookies."
While I agree with your sentiment towards security questions, they are irrelevant when something like that is done. A bit scary.
T3m92uGKhWMRV7Um0WVF50LKQNowpoe0FWwWryL2r9jkuAHyLTCY8QoY79iMiSjo6CHCZGWl
"Your mother's maiden name has four numbers in it?"
"It's a password. You should never use real answers for security questions."
Yahoo used to be a titan. I was a regular user of Yahooligans back in the day. Yahoo (at one time) had been my go to search engine. I can't say that it was ever my primary email account, but I used it. I used Yahoo Messenger. I was part of a community that centered around some Yahoo games. Yahoo used to be a titan that was a direct Google competitor in the realms of communication, search, news and entertainment.
Sure, I can delete an account for any service belonging to any company(!) if I want. But when you use a service, there's an explicit level of trust that they'll protect your information to the best of their ability. We assume that we can use their services as our primary driver without worrying about MD5 hashes without salt. We assume that they'll take more security procedures than a student making a toy app testing boundaries in a 400-level course.
Sure, we can delete our account, but this is an unnerving situation. It's not like Yahoo was thought to be some back alley operation where everyone nervously awaited news like this. Yahoo was a direct competitor and contender to some of the biggest digital companies on the Web. This level of incompetence is mind blowing.
At least it is to me.
Later we saw people ditch their indexes and just using a few big players. Now we have Google, Yandex ..and...Bing? DuckDuckGo uses a combination of Yandex and others, Microsoft has been found parsing Google to build their index ...
I want more options, but the search space barrier to entry is very high.
I really ought to go through and do some janitorial work in there, but some of those are for sites that actually still exist and for which those logins are likely still valid. I don't care enough about them to go log in on each and change passwords, but I also don't want to simply delete them and leave yet another orphaned account.
IMHO you should memorize one very strong password for one somewhat-trustworthy site.
http://penguindreams.org/blog/my-accounts-been-hacked-no-it-...
So yeah, Yahoo's been hacked. Duh...
Finance and Flickr are about all Yahoo is good for any more, and I think my portfolio page loads (instead of 404'ing) maybe 1/2 the time I request it...
(God I really hope they dont mess with flickr though...)
"At the time of the August 2013 incident, we used MD5 to hash passwords. We began upgrading our password protection to bcrypt in the summer of 2013. Bcrypt is a password hashing mechanism that incorporates security features, including salting and multiple rounds of computation, to provide advanced protection against password cracking."
WOW. So basically they did not even salt their passwords until 3 years ago! I knew about the importance of salting password hashes since I was like 17 years old and this mega billion-dollar corporation did not.
Also, they claim:
"Hashing is a one-way mathematical function that converts an original string of data into a seemingly random string of characters. As such, passwords that have been hashed can’t be reversed into the original plain text password."
Which in the case of MD5 is a deceptive claim; even a basic dictionary attack could probably reverse at least 50% of all their accounts' MD5-hashed password (assuming most people use one-word passwords with maybe a few digits at the end).
I got the email this morning regarding the hack, I've not used Yahoo for a long, long, long time, so figured I would go and delete my account.
So I log in, password in 1password is incorrect, no big deal I go to reset it. They send me an email, I reset the password then go through the account deletion process. It tells me my account is "deactivated" and will be deleted in 90 days
...Once that was done I just so happened to look through my emails to see what Yahoo had sent me in the past and I saw that I had undergone the exact same procedure (deleting my Yahoo account, presumably after news about another hack) about 3 months ago but completely forgotten about it.
So what I must have done today was relogged into my 'deactivated' account that I 'deactivated' back in September, which caused it to become active again, then issued a 'deactivate' request again, so now I have to wait ANOTHER 90 days for it to be deleted.
I've made a note of this fact this time to avoid relogging into Yahoo again...
https://motherboard.vice.com/read/yahoo-government-email-sca...
Then I tried to set up 2 factor authentication but I am unable to do it. It keeps rejecting the same phone number as being either invalid or not recognised as a contact, no matter which format I choose to enter it. I've dropped the interational prefix, added it, added and dropped the plus sign, added and dropped the 0 after the international prefix etc etc.
I'd dump yahoo altogether except it's the email for my paypal for over a decade and i can't change that.
Regarding 2FA at Yahoo!, I've also had issues... SMS stopped arriving altogether and I had to disable it.
I can imagine something like re-hashing the existing one with a better algorithm and some salt, and storing new ones solely using the new algorithm + salt. But that introduces some additional complexity because every hash needs information about how it was hashed (MD5 + X vs. just X).
Is there an established best practice for this?
The one I prefer, which you've mostly laid out, is: new passwords are entered as bcrypt(pw) and then stored as "B-$result", old passwords are re-hashed as bcrypt(hash) = bcrypt(md5(pw)) and stored as "M-$result", then your auth function works as follows:
def auth(user, pw):
hash = get_hash(user)
if hash starts with "B-":
return hash == bcrypt(pw)
else if hash starts with "M-":
return hash == bcrypt(md5(pw))
else:
# remove this once you've rehashed your entire database
return hash == md5(pw)
On the login screen, there was a short notice about this breach (with a link to more details), and after logging in I was prompted to create a new password, and update recovery emails / phone numbers.
That doesn't negate any of this shit that happened, obviously, but maybe they're at least gonna try to make things better (we can hope, anyways).
Chrome says "The server presented a certificate that was not publicly disclosed using the Certificate Transparency policy. This is a requirement for some certificates, to ensure that they are trustworthy and protect against attackers."
Probably my Chrome version is too old I guess? (probably not, it's 53 which is only a little behind the latest).
Can anyone enlighten me as to how Verizon compels Yahoo to disclose this information? Or rather, how does Verizon know about these intrusions, if they do?
Yahoo brass probably decided that publicizing this information wasn't worth the PR hit, and so they buried it, but Verizon doesn't want to take on the risk of a potential lawsuit, so their lawyers required Yahoo to disclose it if they want the deal to go through.
It's also terrible that such bad password policies are being pushed onto users, yet no guarantee of security is associated with them.
http://www.businesswire.com/news/home/20161214006239/en/Impo...
"...identified data security issues concerning certain Yahoo user accounts."
Certain...more like all up to that point?
Why not just lock the accounts?
Time to go check HANSA on the onion.
Date of birth : 01/01/2011
nothing
So how are these externalities dealt with where there is no such thing as insurance for this type of breach? There's no way to put the toothpaste (my private information in the form of answers to personal "security questions") back into the tube (only my brain or nearby sphere of influence).
And this goes along with IoT devices that aren't having their known exploits patched by their manufacturers. Similar problem different details.
So without broad laws that say this is wrong and here is a mechanism to attach a tangible cost to this information so a proper risk assessment is done, I imagine we keep seeing this happen with essentially no punishment beyond what Yahoo already is getting punished for.
Are there are "free market types" who actually believe there shouldn't be any form of sanctions whatsoever for causing harm? I've talked to quite a few hardcore libertarians, and I've yet to encounter anyone who takes it that far.
So I'm not sure what the OP means "without lawsuits". Because lawsuits would most likely be their answer here. Also maybe competition from other email vendors who take your security seriously and doesn't leak 1 billion emails? Or pressure from investors not to create that type of liability?
Pretty obviously a strawman, it's far easier to win such an argument with silly caricatures of libertarians as an opponent... someone who believes that all companies should be able to do whatever they want, without any consequence!
Only the most extreme niche of the already niche group of anarcho-capitalists believe in private courts or private law enforcement. Which does not at all reflect mainstream libertarian thought. Who instead wish for a "minimal" state, which at a very minimum means centralized courts.
I've heard economists argue that economies and societies do not exist without some form of a legal system (chiefs, kings, courts, etc). It's the very core of human co-existence to be able to resolve disputes in a fair and just way.
The point of government is to mitigate external and unacceptable risks, and we have grown this system based on experience over hundreds of years. Some super free market types seem to argue that we should throw all that away and then institute systems that, over time, will just reinvent the same things. My guess is they believe they will personally come out on top during the reset period through whatever strength/privilege they inhabit.
I believe that there is no general way to create near-perfect accountability for the statements of people, and that the second-best option is to embrace the uncertainty and develop a finely-honed sense of risk assessment.
It sounds like this is the underlying concern -- if you are unable to appropriately assess risk, and you place your trust in an organization that then betrays your trust, you feel violated and want to work toward preventing that sense of violation in the future.
You could do that by working to hold organizations accountable through regulation or other means.
Or you could improve your ability to assess risk, and consciously and deliberately accept risks as they come. When the inevitable adverse event happens, you understand that you consciously accepted a risk in the past, and appreciate the opportunity to refine your own personal ability to evaluate risk.
So, I don't agree that this is something that needs to "get fixed". I fully expect that my basic personal information is poorly secured, and I consciously accept that in exchange for the benefits of participating in our current society and using the current services offered.
It's easy to say that "we need better information security", but every decision has a tradeoff. Increasing security fundamentally increases costs, slows the flow of information, and creates less nimble organizations. Many of the services you expect to be available -- Uber, cheap IoT devices, whatever -- may simply not exist in a world where a "proper risk assessment" and "tangible cost" of information breaches are applied.
You, of course, are free to spend your time educating the public about information security, or how corporations can't be trusted, or even lobbying for information security regulation. That's what makes Earth fun and interesting -- everyone's following their own passions!
There is insurance. Some of the breached accounts likely contained credit card info, and any exploits are covered by existing insurance.
Some of the accounts might contain embarrassing emails, but few people have insurance against hacked disclosure of that sort.
Things like this happen because the public doesn't care. Most people who use Yahoo for email are computer illiterate and are more likely to do things that lead to a breach. They are also more likely to quit using the service if things like 2FA are required.
So in a sense, the invisible hand delivered the service that was demanded, and now the market can correct. Some percentage of the users impacted will learn from the experience and demand higher quality email hosting in the future.
This being what exactly? What is a threat model you are talking about? Because it sounds like you think that a typical user account used for porn, social sites and hobby is worth protecting somehow to the extent of government involvement.
I learned long ago, never to wrestle with a pig. You get dirty, and besides, the pig likes it. Read more at: https://www.brainyquote.com/quotes/quotes/g/georgebern137450...
I'd be sufficiently curious to find a single person who fits the profile of the ideologue the OP is referring to. I'm afraid such a person doesn't exist.
Uh, it's been 4 years... I know, time flies.
JUST