Showing posts with label email. Show all posts
Showing posts with label email. Show all posts

Saturday, 5 November 2011

Flaw in email security means signed mails cannot be encrypted

I was at a company the other day that uses a well-known email encryption solution as they have some very sensitive information that they need to send both internally and externally. As is common for these solutions, it is possible to automatically sign the email by putting a keyword in the subject line, such as 'signemail'. Similarly, the mail will be encrypted automatically if the confidential flag is set or a keyword, such as 'encryptemail' is added to the subject.

So far, so good. There are no messy button presses or extra steps for the user. However, there is a flaw with the solution. (I should point out that at this moment it is unclear if it is a product problem or a configuration problem, hence my not mentioning the product.)

The issue is that the signing the message appears to take precedence over encryption. So, if you add both keywords to the subject then the message will only be signed and not encrypted. Now the encryption solution does also sign the message, so if you want it encrypted then you don't need to specifically sign it as well.

So is this really a problem or am I just making a fuss? Well, I can envisage several situations when it would be a problem. The most likely is probably replying to a signed message with confidential data. Let's say that Alice puts in a request for sensitive information from Bob via a signed email - only certain people can have access to the information so it is reasonable to expect Alice to digitally sign the request, but the request is not sensitive in itself.

Now, if Bob replies to that request with the sensitive information attached he will follow policy and mark it as confidential and add the encryption keyword, 'encryptemail', to the subject line. He will now assume that the information will automatically be encrypted. However, if he doesn't remove Alice's 'signemail' keyword it will just be signed and not encrypted. This then violates the policy and sends confidential information in plaintext while the user believes that it has been encrypted.

It also highlights that you shouldn't use a keyword that might be used as part of everyday language. For example, don't use the keyword 'sign' as someone could send a sensitive document with a subject something like 'Contract for you to sign'.

I suggest that everyone using this type of solution should test it to see if this happens on their system. If it does, you will, at the least, need to publish an advisory warning to your users.

Wednesday, 12 October 2011

Sony to send password reset email

Sony have detected someone trying to gain access to their various networks again, by using ID and password pairs that Sony conclude have been extracted from someone else's network. This may be a valid conclusion as it was only a small percentage of users that were affected (less than 0.1%, which is still 93,000). Sony have been upfront and quick to react, disabling the affected accounts and putting out a notice.

However, their next step, according to the notice given by their Chief Information Security Officer (CISO), is to send all the users who have been affected an email asking them to change their password.

Cue phishing scam!

Surely some bright spark will now construct a phishing email to send out to everyone saying that theirs was one of the 93,000 IDs compromised and could they now change their password. A simple copy of the site would then enable someone to lift thousands of valid credentials from accounts that weren't compromised. The problem is that Sony's users are now expecting an email to arrive to tell them to change their password. The work to trick someone to follow a link has already been done by Sony and the media.

How about not sending an email? Instead, publicise the attack and that some accounts have been disabled (Sony has done this). Next, let the users come to the Sony sites and try to log in. Then you can inform them that their account has been disabled and what the password reset procedure is.

Tuesday, 11 October 2011

Password Protect Your Mobile

I know that many security 'professionals' will scaremonger and preach doom and gloom at every turn in order to drive up sales. However, they're not always wrong. I read the article 'Mobile device users fail to take basic steps to protect themselves, survey finds' and wanted to relate an event that happened this weekend. Many people are saying that mobile device security threats are hype and that nobody is actually exploiting them. That's possibly true to a certain extent at the moment, but for how long? Another article claims that identity theft is now more profitable than car theft! A mobile phone is a very good start for this purpose.

An interesting figure that comes from the article above is that 160,000 mobile phones are lost or stolen every day. I assume that this is just in America, as in Britain the figure is around 20,000 a day. Whether or not these figures are accurate is immaterial, the fact remains that a lot of phones go missing. What do you have access to from your mobile?

The recent incident that I mentioned above happened on Sunday. Someone left their iPhone at a sports training ground I was at. On inspection of the phone, there was no authentication set on it at all. I was able to see photographs, names, addresses and telephone numbers of family and friends. In addition to this, they had a Facebook App, which was still signed in. It would have been very easy to update their status with a malicious link for all their friends to visit. Worse than this, however, was the fact that they had access to their corporate email and address book from the phone - a FTSE 100 company. Again, this was still signed in with no additional authentication required. What corporate information could I have gained access to?

As it was, a phone call to the telephone number entered as 'Home' enabled the phone to be returned without stripping data off it or sending phishing messages. However, what if someone else had picked it up? The survey in the article stated that, of those interviewed, over 65% used their mobile phone to access corporate email and networks. "Do you send or receive sensitive information via email?" should have been the next question.

Businesses and employees should think carefully about the data held on their devices and the level of access they have to the corporate network. At the very least people should always have some form of authentication set on their phone, e.g. a PIN, password or stronger authentication. The majority of users leave applications, such as email and social media accounts, perpetually logged in and many users leave their devices unlocked. Even when they are forced to lock them due to policies, they don't always really secure the device. I have seen many users with corporate phones that require passwords use simple passwords (such as 'qwerty') so that they are easy to type. They site difficulties in typing complex passwords as being the major reason for choosing simple passwords, which is in line with the findings of the survey.

The bottom line is that these devices are part of the corporate network, whether the IT department is aware of them or not. They need protection. Even as an individual, protect your identity and your contacts by employing automatic locking of your mobile with passwords or long PIN numbers and don't leave apps permanently logged in. (I find it surprising/worrying that I have to give this warning/advise!)

Friday, 3 June 2011

Google email Accounts Compromise

I was asked to comment yesterday on the story that emerged about the Google mail accounts that were compromised over the last few days, so I thought I'd put some of my answers down here. First off, Google wasn't compromised; a set of phishing emails were sent out and a fake Gmail login set up to harvest login details. These were used to set up forwarding rules to copy mail to another account.

Unfortunately, although a large number of people are aware of phishing and are (to a certain extent) vigilant, it only takes one person within the organisation to fall for the attack to compromise security. The scammers are becoming better at targeting people and making the initial phishing contact more believable to some people. Phishing is not just about email, although that is the most common avenue for the initial contact. Social media is also commonly used and we have seen the use of SEO to force phishing sites to the top of search engine rankings as well. User education is the only real way out of this.

Could this be cyber espionage? I would think that is most likely given the profile of those targeted. Information is worth a lot of money and political weight. In recent years we have seen a decrease in attacks designed to deface/destroy/delay/deny services and information. Instead, we are now seeing information and identity theft as major goals. Viruses won't necessarily stop your computer from working, but they will use Trojans to steal your login credentials. Malware now will silently sign your machine up to botnets rather than perform an obviously malicious action.

What can companies like Google do to stop this? Well, they can improve their SPAM filtering for a start. It is possible to eliminate the vast majority of phishing emails, which would drastically reduce the problems. However, many of the major vendors aren't strong enough on this. Secondly, user education would help a lot, but can't always help you against the best social engineers. To be honest, though, the governments and organisations that these people work for shouldn't allow the use of gmail, or other accounts (which have fewer controls than a corporate email setup), for official business and should educate their users to use different passwords, be vigilant, etc.

Spear phishing is a more difficult one to combat as it targets a specific user or group of users that the attacker has knowledge of. If I know your habits and who your friends are then I can use that information to trick you much more easily. If you receive an email or Facebook message from your partner, do you hesitate before opening it? The reason this doesn't happen more is that it takes background research and, by definition, targets very few people. This technique is only relevant if you want what that specific user has access to. Hence it is more likely to be information that they were after.

Another way to combat these types of attack is to use one-time passwords as well, so that intercepting a single logon only gives you access during that session, and isn't valid in the future. However, tokens are prohibitively expensive for Google to hand out to everyone. There are other solutions such as SMS tokens, but these aren't all that cheap, when multiplied up by the number of gmail users, and aren't without their problems. Software token solutions such as Swivel, GrIDsure, FireID, etc., are possibly cost-effective enough to be implemented and could drastically reduce the success of these attacks. However, none of these stop the man-in-the-middle (MITM) attack, so you could still hijack the session and set up a forwarding rule to obtain a copy of all their mail. Google do allow you to set up alerts and have to validate changes through a 2-step process, but you have to enable this. This should be the default for all of these services. Perhaps they could also add a footer to all versions of the email to specify where it has been forwarded to.

How worrying is this sort of attack? Well, that depends. Most people can be socially engineered - look at Derren Brown! For the individual, spear phishing is unlikely to be a problem, but with a lack of education they may well fall for a bulk phishing scam anyway (thousands do or nobody would bother). However, for those with access to secrets or other valuable information, it is a serious issue. It all comes down to how good the attacker is. I believe that HM Treasury is the most attacked entity in this country and that is mostly for information rather than evading tax or performing Denial-of-Service, etc. They should be worried about this type of attack.

Thursday, 20 May 2010

CQC Using Email to Verify Care Workers

The Care Quality Commission (CQC) has decided to put registration of Care Providers online to make everything faster and easier for the providers. At least that's what they said. In practice, care providers had to fill in the online forms addressing standards that won't be published for another 5 months after the registration deadline. Ignoring all the problems, ridiculous re-branding to avoid inconsistencies and money wasted, there was a serious problem/lack of understanding that has lead to this blog post.

All care providers and managers have to register online individually and have to agree to particular terms in order to be registered and, therefore, trade. I have no problem with this as these care providers are looking after vulnerable people. However, it became obvious that there are serious problems with their system. First off, it isn't possible to change the owner's name if you make a mistake (they can't change it either apparently). Therefore, if you make a mistake, you now have to lie to say that all the details are correct, otherwise you can't register and you'll be out of business - not a good start.

However, this is overshadowed by the fact that the CQC uses only email to verify care managers. First of all they sent a 6-character password to the main business email address with the URL and details of how to log in (no paper verification was done at all). Don't they realise that email is all sent in plaintext and can be read by anyone with a packet sniffer? When logged in, the care provider has to fill in some initial forms as the owner and then list the care managers that they employ. Following this, each care manager is sent a 6-character password via email in order to log in and register their care service. There are a couple of problems with this. Firstly, the email addresses are just entered during the initial form filling exercise and are not checked and secondly, you can't reuse the same email address. So if you are the manager for more than one care service you have to use two different email addresses. The stupid thing is that they accept any email address from an alias to the same mailbox through to hotmail accounts with no checking at all.

They don't seem to realise that half the email addresses people use are just aliases onto other email accounts. On one of my accounts I have 9 email addresses all delivering mail to the same mailbox as they are various options of name and domain all relating to the same company. However, CQC would treat this as 9 different people. There is no checking done to see if that really is the care manager at all. Anyone could sign up as long as they intercept the initial password. Who has access to the standard email address for the organisation? Usually several people and usually not the actual owner of the business - the only person who should receive that email. Due to the way their system works, if someone were to intercept that email (such as a disgruntled ex-employee) they could sign up with a random free email address begin the registration process, not complete it and put the care provider out of business as they won't have registered in the set time.

This is mostly a PR exercise as far as I can see and a bad one. They say that they are checking providers and improving standards. However, it is perfectly possible for the owners and managers to be completely unaware of their registration process because no actual checking is done. In addition, to assume that two email addresses entered into a website are for two different people, and base your authentication on that, shows a lack of understanding of the technology that they are forcing on people.

Edit: 13/7/10

I sent an email to the CQC about this issue and being able to hold people to it legally a while back and a few days ago I received a reply. Here is the main bulk of their reply:

"Thank you for taking the time to write to us and we would acknowledge that the
points you correctly make present some element of risk. To reassure you, and
your customer, we were previously aware of each of those points and have
considered, with our compliance and legal teams, the balance of risk that they
present and any difficulties with legal status that could result, before making
a positive decision to implement in this manner."
"To further reassure you, we commission independent penetration testing of our systems prior to go live to assure their security."
I did ask to see one of their security assessment reports, but was (unsurprisingly) turned down. I understand that they don't want everyone to know how their systems works as that could reveal further problems, but I would like to know what was actually said about this issue and how they justify it.

Friday, 30 April 2010

Surveys or Phishing Emails?

I was recently sent a survey from a well-known survey company (actually, on second thoughts, I'll name them: Capita) and it made me very cross. Why so cross? Well, I spend a considerable amount of time trying to educate people about their role in the security of the network and about phishing/social engineering. This is all undone by survey companies such as the one in question. See for yourself the email sent and use it as a template for future 'white-hat' testing.

Have your Say! Fill in your Staff Survey today!

Dear Colleague

It’s important to complete the Staff Survey to ensure your voice is heard! The purpose of the survey is to make further improvements to staffs’ working lives at Target Organisation.

Your responses will come direct to Capita Surveys & Research Unit, and will be totally anonymous. No one outside the research team – and certainly no one at Target Organisation – will know who has responded or be able to identify individual responses. The survey findings will be analysed by Capita Surveys & Research Unit and only aggregate results will be reported.

To ensure that you have adequate opportunity to participate, the survey closure date is date month year.

In order to participate in the survey visit:

https://sas.capitasurveys.co.uk/targetorganisation

and enter your password: AAdddd

If you have any queries or require support completing the survey please contact us at Capita Surveys & Research Unit on 0800 587 3115.

Yours sincerely

Cheryl Kershaw
Director of Surveys and Research
Capita Surveys & Research Unit

What's wrong with this? Many things! Phishing scams are on the increase and are one of the biggest threats to security at the moment. Targeted phishing, or spear phishing, is also on the increase and these surveys could easily fall foul of this type of attack. The survey emails are in a standard format with no personalisation. It appears as a classic phishing email, albeit with better grammar. It would be easy to exploit this 'legitimate' survey to ask for additional personal details. Points to consider:

  1. There is no personalisation – ‘Dear Colleague’
  2. The email doesn’t come from the organisation in question – staffsurveys@Capita.co.uk
  3. The URL does not point to the organisation in question – https://sas.capitasurveys.co.uk/organisationname
  4. There is no contact within the organisation presented in the email for confirmation – contact Capita Surveys & Research Unit on 0800 587 3115
  5. They do not use an EV SSL certificate on their site, only DV – QuoVadis Global SSL ICA certifying that this is sas.capitasurveys.co.uk, which could be a phishing site for all a user knows, as it isn’t certified to be Capita or Capita Surveys & Research Unit (see post on EV versus DV certificates)
This would be very easy for someone to impersonate, particularly if they register a similar URL, such as https://sas.crapitasurveys.co.uk/organisationname and then use masking as well. Users are being conditioned into clicking on links without questioning their validity. All I would have to do is know (or guess) that this organisation conducts surveys of this type from an organisation like this. OK, Capita suggests that organisations publicise the survey, but this isn't always done well and can be used to produce a fake version before the real one goes live.

It gets worse though. When I phoned Capita Surveys, a nice helpful lady called Liz told me who they were currently providing surveys for (I won't give out the organisation names here as that would be irresponsible, but if Capita would like to check with me I can prove this). It would be very easy to quickly knock up a copy of their site with a similar URL and registered SSL Certificate, add in a few extra questions, send those emails and wait for the information to roll in. Well done Capita! They say they take people's security seriously and that answers are secure because they use SSL. However, I would beg to differ.

Capita aren't the only culprit though; I was also recently sent a survey for Microsoft from Mori, which was just as bad. They have to take steps to ensure that their surveys can't be hijacked for targeted attacks. There are anti-phishing technologies and techniques available that, whilst not infallible, would help, so why aren't they used?

Thursday, 14 May 2009

InfoSecurity Europe 2009

Well, a couple of weeks ago I went to InfoSecurity Europe 2009 at Earl's Court, as I do every year. If you've never been, but are at all interested in network and information security or are looking for vendors, then I highly recommend visiting. To my surprise, and for the first time I can remember, Microsoft wasn't there. Apart from that, however, all the usual players were there and, to be honest, it was all much the same as before. There was no new emerging technology or hot topic, just new developments of old technologies. A couple of years ago we had the hot topic of 'social engineering' and 'securing the user'; ok, we all knew that the users were our weak link and phrases like "we spend all our time securing the first 2000 miles and forget about the last 2 feet", and "our network would be totally secure, reliable and fully functional if we didn't let users login", have always been commonplace, but there were new mass threats, new education programmes and new tools at the disposal of net admins to deal with them.

However, this year was different; nothing really sprang out. OK, cloud computing and Software-as-a-Service (SaaS) has expanded and matured, but other than that we see the same products and services as before. What amazes me is how some vendors and speakers can get it so wrong and don't appear to understand the actual level of security offered or operating environment in which their products will be used. I'm not going to list actual vendors here, but how can an encryption solution for mobile users that doesn't encrypt the data at rest be viable? Encrypting network traffic is commendable, but not the only safeguard required. What if they now lose their laptop, mobile or pen drive? A secure USB pen drive vendor admitted, when questioned, that files were decrypted into the C:\Temp folder while in use, then deleted after encrypting for storage on the drive again. They couldn't tell me if this was a secure delete or a simple removal of the pointer in the file allocation table as normal. Regardless of the deletion process, however, how many applications can read and write to that folder? What's to stop me from writing a very small bit of code to monitor that folder every few seconds and take copies? This might be secure enough if it is on a corporate machine, but why not just store the file on it then and not bother with the drive?

Similarly, email security is always a problematic area, with almost no solution fitting the technology properly. The big advantage of email, and the reason we all use it, is that it is independent of firmware - i.e. it doesn't matter what hardware, OS or email app we use, it still works. Unfortunately, security was never built in to email, so every email is like sending an electronic postcard. However, I would argue that a solution that only allows you to send encrypted email within your organisation is of limited value. What about all your customers and partners? There are also still solutions that store your files on their servers and send a link to the recipient. Why trust your files to them? I asked several vendors how they deal with password transfer, only to be told that they don't. "It's up to the user how they tell the recipient what the password is," was a common reply. We know users are unreliable, why leave it to them? I had to transfer some confidential files to someone via email recently (the only transport method they would accept), only to be told that they didn't want the hassle of decrypting it, so could I send them in plaintext. Having got over that hurdle, they wouldn't give me a mobile phone number so that I could transfer the passphrase via a call or SMS (as people seem to need them written down), asking me to email it to them. I know there are technologies out there to solve these problems, but they aren't without any problems.

This is turning into a bit of a rant and I'm getting off topic, so back to InfoSec. I was pleased to see that there were some voices of caution out there about the wholesale adoption of virtualisation without considering the security implications. One that springs to mind is Steve Moyle who has produced 10 points to consider implementing on his blog here. Virtualisation is a good technology for a number of reasons, but it does bring in new security threats and it must be implemented with these in mind and secured accordingly. I do also think that cloud computing and SaaS could be very important to SMEs (Small to Medium-sized Enterprises) who don't have the in-house expertise or large budget. They can still have large enterprise-level configurability and security, without the overheads. Finally, people seem to be taking information governance and user education seriously rather than just paying lip-service to them. In all, the show was encouraging, but many vendors are not quite there yet, which only goes to highlight that the majority of organisations are not taking the new threat-landscape seriously enough and countermeasures must be lacking.

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