Tag Archives: twitter

Old News: Twitter can be used for Botnet Command & Control

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Shocking but true…today a researcher discovered that Twitter has been used for command and control of a botnet which may have been used by Brazilian hackers to steal online banking login information.  Kudos to the researcher, Jose Nazario, who found this.  It was an interesting read to say the least.  The bot would basically look for base64 encoded commands on a Twitter account to download malware via RSS feeds with obfuscated (shortened) URL’s.  Interesting…sounds a lot like Robin Wood’s tool KreiosC2 which was released at DEFCON 17.  I even did this demo showing what else? Base64 encoded commands.  Ironically, I showed off the first version of this code at Notacon 6 back in April of this year.  Keep in mind, KreiosC2 can be used for legitimate tasks like controlling things at home remotely via Twitter.  I highly recommend you read Robin’s detailed write-up on how KreiosC2 functions.

What I find fascinating (like most things in security) is that now that there has been a real confirmed case of using Twitter for botnet C2 (Command & Control) the media seems to be jumping on it and even trying to determine “why it took so long for hackers to take Twitter to the dark side”.  Well, you can’t say we didn’t warn you.

The point that Robin, myself and others were trying to make way back in April was that this is a real threat and the bad guys have probably started to use Twitter for C2 even before Robin put out the code!  We were hoping that by releasing the code Twitter (and others) would see this as perhaps an early warning of things to come and perhaps prepare some defense for it (yes, we know it’s hard to put a defense together for something like this).  Now that we have a confirmed case used for malicious purposes we hope Twitter takes this seriously and can combat future C2 channels used for very bad things.  It always takes something bad to happen to create change…where have you heard that before? :-)

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Social Zombies Slides and DEFCON Updates

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tom_kevin_zombieKevin and I want to thank everyone that came out to our talk at DEFCON 17 this past weekend.  We had a great time giving the talk and thanks for the feedback!  Even the two Facebook developers that came to our Q&A enjoyed it!  Having said that, Kevin and I will never, ever get a Facebook party invite while at Black Hat and/or DEFCON.  Oh well! At least @dualcoremusic got to play live! :-)

You can download the slide deck from SlideShare that was in the DEFCON 17 CD.  We plan on giving the talk a few more times in the next few months so we don’t plan to release the full version of the slide deck yet.  However, we will post the video as soon as we get it.  The slides on the DEFCON CD are mostly text…no cool Zombie graphics (thanks to @JaneDelay for the Photoshop work BTW) but it should give you a good overview of the talk.

Robin Wood’s fantastic tool called KreiosC2 was also released during our talk.  I did a demo which is posted here and talked a lot about how the PoC code functions.  If you don’t know already…KreiosC2 is a tool written in Ruby which allows IRC like command and control of systems over Twitter.  Very cool!  Also, check out the redesign of Robin’s website.  Awesome.  Make sure you follow Robin on Twitter!  He is one you need to follow!

DEFCON was awesome as usual!  Lot’s of people this year..perhaps an increase from last year and of course the usual hijinks.  It was awesome catching up with everyone and meeting new people.  I attended lots of great talks including the “DEFCON Security Jam 2: The Fails Keep on Coming“.  This was one that you should see the video for…especially the presentations by @haxorthematrix and @myrcurial.  Speaking of @mycurial…you really need to see the awesome yet scary presentation that @myrcurial and @TiffanyRad did on Sunday titled “Your Mind: Legal Status, Rights and Securing Yourself“.  I highly recommend this talk!

The podcasters meetup was also a success!  Thanks to @pauldotcom for hosting and for throwing such an awesome party this year and a shout out to the guys over at I-Hacked.com!  The audio will be posted soon, probably over at the Security Justice site.

Pictures will be posted soon!  Still trying to recover from Vegas!

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Another Twitter Scam: Twitviewer

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twitviewerOne of the trending topics today on Twitter was “Twitviewer” becuase of a site called Twitviewer[d0t]net which asks visitors to enter in your Twitter user id and password to find out who is “stalking” you.  When you do, you get a sample of people on Twitter that are not even following you as stated in this Mashable post.  The app also sends out a tweet using your credentials stating: “Want to know whos stalking you on twitter!?: hxxp://TwitViewer[d0t]net”.  If you did fall victim to this you better change your password ASAP!  Check out the screenshot of the site before it was taken down…yeah, phishy indeed.

Who knows what the developers of this application were planning (malicious or others).  Regardless, you should never give a third party site (especially ones that look phishy like this one) your Twitter credentials.  In fact, I recommend you only use third party Twitter sites that use OAuth for authenticating you to Twitter.  That way you don’t have to give your credentials to the web site and worry about them being compromised.  Also, look to see what the purpose of the site is before you give the jewels away…if it’s a way to see who’s following you, enter credentials to get millions of followers, etc…then it’s probably a scam or just completely useless.

Think about this.  If the developer of a site like this wanted to they could easily use your captured Twitter credentials and start trying them on other social networks and/or web mail services.  They can then use these credentials for anything else they wanted.  Unfortunatly, most users of these sites use the same password for everything.  Again, this is a reminder to use a password manager if you are one of those that use the same user id/password for everything.  See this article for more information on password managers and social media web sites.

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Social Zombies Invade Las Vegas!

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zombieYes, you are reading the title of this post correctly!  Massive Zombie attacks at DefCon this year…bring your shotgun (we are kidding of course, please do not bring firearms to DefCon…you will make the goons very unhappy)!  Seriously though, Kevin Johnson and I will be presenting “Social Zombies: Your Friends Want to Eat Your Brains” at DefCon 17 in Las Vegas on Sunday, August 2nd at 4pm.

My part of the talk is focused on security and privacy concerns with social networks, fake accounts, using social networks for penetration testing and the proliferation of bots on social networks.  I will also be talking about a new version of Robin Wood’s fantastic “Twitterbot” (we actually have a new name for the tool which will be announced at DefCon).  I’ll be providing a live demo showing the new and improved features of his tool!  Big shoutout to Robin for all the work he did on this tool!

The other speaker is Kevin Johnson who you may know as the project lead for BASE and SamuraiWTF (Web Testing Framework).  Kevin is also a SANS instructor for Security 542 (Web App Penetration Testing and Ethical Hacking).  When he isnt managing projects and teaching he’s most likely abusing “playing with” social networks.  Kevin will be talking about SocialButterfly which is an application that can leverage and exploit various social network API’s.  He will also talk about manipulating social networks (and thier users) with third-party applications.  Remember: please accept any and all “friend requests” from Kevin Johnson! :-)

From our talk abstract:

In Social Zombies: Your Friends want to eat Your Brains, Tom Eston and Kevin Johnson explore the various concerns related to malware delivery through social network sites. Ignoring the FUD and confusion being sowed today, this presentation will examine the risks and then present tools that can be used to exploit these issues.

This presentation begins by discussing how social networks work and the various privacy and security concerns that are caused by the trust mass that is social networks. We use this privacy confusion to exploit members and their companies during our penetration tests.

The presentation then discusses typical botnets and bot programs. Both the delivery of this malware through social networks and the use of these social networks as command and control channels will be examined.

Tom and Kevin next explore the use of browser-based bots and their delivery through custom social network applications and content. This research expands upon previous work by researchers such as Wade Alcorn and GNUCitizen and takes it into new C&C directions.

Finally, the information available through the social network APIs is explored using the bot delivery applications. This allows for complete coverage of the targets and their information.

How did this talk come together?  Kevin and I had some past converations regarding social network bots (mostly from my Notacon 6 talk) and decided that much of our research was similar so it made sense to “combine forces” to work on some of this research together.  Also, by working on bots and socnet bot delivery mechinisms we hope to raise awareness about some of the security and privacy threats that are out there, not just for the users of social networks.  Oh, and we both like Zombies.  See you at DefCon!

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Password Length and Complexity for Social Media Sites

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July 1st was “Twittersec” day as coined by @hevnsnt over at I-Hacked.com to designate July 1st as change your Twitter password day. Why? Mostly because July is the “month of Twitter bugs” created by a security researcher in which he will announce a bug in a “3rd party Twitter application” everyday for the month of July to raise awareness on security issues with the Twitter API. Technically, this should be “month of 3rd party” Twitter bugs but whatever. Either way it will raise awareness about some of the security issues of Twitter and 3rd party applications.

ANYWAY, back to my point….I sent out some tweets about changing your Twitter password and now being a good time to use a password manager like Keepass to manage multiple, complex passwords for everything…not just social media sites. One problem though is that each site might have different password length and complexity requirements. This becomes an annoying issue when you choose a randomly generated password like I suggest when using a password manager. You will encounter many sites that have specific requirements and others that do not. Obviously, the longer and more complex the password is the harder it is to crack so I suggest going as long as you can. Sad that there are these limitations on certain sites (blame the site developers) but if you set your random password generator to a very large number (I recommend at least 20 with a mix of everything you can throw at it including white spaces if the site will let you), it’s as good as your going to get.

Keep in mind, some applications even supported by the site (like the Facebook app for BlackBerry and iPhone) might not like passwords over a certain length or even certain special characters…you will know once you use these apps. Also, I mention Keepass as a password manager because you can use it on a BlackBerry or Windows Mobile device as well…an iPhone version is being worked on. So here you go…max password lengths for the major social media sites:

Twitter
None. I tried a 500 character password with everything but white spaces and it worked.

Facebook
None. I tried a 1000 character password with everything but white spaces and it worked.

MySpace
10 characters! Wow…really bad. Now I know another reason MySpace sucks.

LinkedIn
16 characters! This is interesting. LinkedIn truncates the password to 16 characters! Even if you put in a password larger then 16 characters it will only use the first 16, you can actually see this when entering in a password. No user notification, no info about this in the ‘help’ section. Sneaky and evil.

YouTube
None. Your account is tied to your Google account so is kind of a pain to change…but I didn’t find any issues with length or complexity.

On another note…I wonder if Twitter and Facebook truncate the passwords at a certain length and don’t tell you? Not sure…but it would be interesting to find out. This is another bad design as a they could easily just hash the entire password (which is a certain manageable length) and the hash is stored in the database not the large character password. Does this mean that sites like MySpace and LinkedIn are storing passwords in clear text? Also, I have run into other sites (non-social network) that actually truncate the password because when you try to login with an overly complex password…you get denied! Then you enter the cycle of doom…resetting your password thinking you fat fingered that password to begin with over and over. :-/

Are social media password limitations working against you?
Finally, just a quick point on this. Social media sites like MySpace and LinkedIn should NEVER have any limitations on password length or complexity. Certain complexity restrictions (like white space or strange characters) I could understand since you would have to use these passwords on mobile devices and other integrated apps. However, there are no technical limitations of just hashing the passwords to a constant length…and we all know storing passwords in a database in clear text is never a good thing.

Shouldn’t these social media sites that you already give your personal information to be trying to protect you the user as best as they can by letting you set a long and complex password? Let’s hope MySpace and LinkedIn get better at this real soon!

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Establishing your social media presence with security in mind

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If you have been using social media or are curious of the security of this emerging technology you may be interesting reading my recently published article in issue 21 of (IN)SECURE Magazine. In my article I discuss why companies are starting to use social media, the benefits/risks and what information may be posted about your company on social media/networking web sites. I also talk about some cost effective tools your company can use to start your own social media monitoring program (without spending a ton of cash) and how to put in place guidelines for employees regarding the use of social media. Yes, even if you block these sites in the workplace employees are going to use social media/network sites outside of work if you like it or not…you had better get used to it and adapt your policies!

This article started from me actually seeing how much information there is about businesses within social networks. Both good and bad! The information I have found has been extremely valuable when conducting penetration tests. In fact, this information can be so valuable that you may be surprised how easy it is to use this information for social engineering or more…the possibilities are endless. As I pointed out in my article, get together with the business leaders in your marketing and/or public relations group and talk about social media and how to use it with a bit of security and privacy in mind. You might be surprised how receptive they are to the input from a security professional!

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Twitter for Information Gathering

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Twitter!

If you are interested in using Twitter for information gathering/mining about potential targets for a penetration test or for “other” research…I highly recommend the very comprehensive article that Lenny Zeltser from SANS put together. Twitter is really becoming a great tool for not just marketing yourself or your business but also to find out detailed information about a company, individual or organization.

One thing I would add to Lenny’s article is that social media in general is the new “hotness” when it comes to information gathering and reconnaissance. If you are a penetration tester you really need to start leveraging all the information contained in social networks! Better yet, use Maltego which can help search multiple social networks and visually show you this data. You can even hit up the Twitter API with local transforms in the new version of Maltego…yummy!

Twitter photo via Jenny Hayden.

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Summary of the Twitter Security Incidents

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One of the 33 pwnd Twitter accounts

I won’t beat a dead horse…we all know that Twitter had a few *security issues* this week. The good news is that usually once something like this happens to a company (especially one that gets so much media attention) things start to change and security gets taken a bit more seriously. Lets remember that Twitter suffers from the traditional security problem of not building an application with security in mind, however, lets hope these issues bring change to one of the most used social media services.

Below is the break down of events with some of my own comments and links to good articles that detail out everything that happened.

#1 Twitter Phishing Attack
I wrote a blog post about this a few days ago. Basically, this is no different then what you see in any other traditional phishing attack except that this is the first time Twitter was targeted on a large scale. Some have even said this was a “worm” because of the way that the phish propagated.

Once a user clicked on the bogus link, entered in their Twitter credentials…their Twitter account was compromised and automatically used to send DM’s (direct messages) to others the compromised user was following. Twitter quickly reacted and worked with blogspot and others to shut down the redirect. However, the web site that hosts the fake Twitter sign-on page is still active and is even being used to phish Facebook users! Why is this not shutdown? Long story but the site is hosted in China and that presents a whole host of issues to get the site taken down. The good news is that if you try to go to the URL in Firefox or Safari the phishing filter kicks in and stops you from going there. I haven’t tested IE 7…and neither should you. :-)

On a side note, I agree that OAuth (or something like FriendFeed’s Remote Key) should be implemented as part of an overall security strategy for Twitter but would not prevent traditional phishing attempts like this from happening (some others share this opinion as well). OAuth is good for authenticating third-party applications (like Twillow or Twitterfeed) that require your Twitter credentials to access your account and do things on your behalf. Lot’s of discussion going on the blogs about this and I’m sure it will continue.

Links that have good information about the Twitter phish: Twitter’s Blog, Naivete: Web 2.0′s biggest security threat and an article over at Twitter Truth

#2 Twitter gets Hacked
This was not related to the phishing incident. Pure weird coincidence that this happened right after users started to figure out what happened with the phishing issue. Ironically, many of us on Twitter (including myself) thought that this was related to phishing after we saw @foxnews get owned but once Britney Spears, Obama and others started showing up with strange tweets many of us knew there was something else going on.

Basically, an 18 year old who wanted to “pen-test Twitter” decided to build a Twitter brute force application that would try common dictionary words against at specific Twitter account. One problem with the current Twitter security model is that there is no lockout policy, meaning, you can try as many failed passwords as you like until you get lucky with the correct password. This guy found one of the accounts used by the Twitter support people (Crystal) and brute forced the password using his tool. Password of “happiness” was found and he was in! There was a password reset feature in the administrative panel that allowed him to reset the password and change the email address of any Twitter account. He didn’t use the accounts himself, rather…he posted that he had access to 33 accounts and gave access to others in a hacker forum that requested the accounts. You can read more about this in the Wired article below as well as see the YouTube video that the hacker put up to prove he did the hack.

Weak Password Brings ‘Happiness’ to Twitter Hacker

How does Twitter get fixed?
Security is always about compromise and with Twitter in particular there has to be a balance between usability and secure features. I was a guest on the SecuraByte podcast the other night talking about the recent Twitter security issues as well as how to secure social media in general. We came to the conclusion that there is no good answer. However, we all agreed that there has to be a mix between technical and non-technical solutions. The technical being better forms of authentication and basic web application security controls (account lockout, email verification..as examples) for starters. On the non-technical side there has to be more basic security education (setting unique hard to guess passwords as an example) focused on the users of social media through lots of different means. There is no good answer to these problems and there are many different opinions but hopefully we can all come to some common ground so we can all make social media more secure for everyone.

Here are a few good links with things that Twitter should consider when re-evaluating the current model:

Ten Security Measures for Social Networking sites – ThreatChaos
Twitter and the Password Anti-Pattern – FactoryCity
The inevitable rise (and fall?) of “twishing” – Jennifer Leggio ZDnet (guest post by Damon Cortesi)

I think we can all agree that Twitter needs to do something soon as the current security model is not sustainable for very much longer.

What are your thoughts on the recent Twitter security issues and social media security in general? How do you think we can we make social media more secure?

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First Twitter Phishing Attack of 2009

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Welcome to 2009! As many have said…it was just a matter of time before Twitter had a somewhat significant attack…well, here it is! I just had a post up last week about how many of us that use social media just blatantly trust every site that asks us for Twitter credentials. Well if you don’t look at the URL carefully even the security aware could be fooled by this one. Tonight there was a lot of tweets about the following phishing attack….

You will get a DM (direct message) in your email from a user with the following message:

hey! check out this funny blog about you…
hxxp://jannawalitax.blogspot.com

If you click on blogspot link this is basically a redirect to the following fake Twitter site:

Twitter Phishing Site

Looks just like an identical copy of the real Twitter site except for the URL! (don’t go to this URL…)

About an hour after this started going around Twitter it looked like Firefox 3 picked up that this was a reported phishing site and you now get the following message:

Web Forgery Reported

Looks like Twitter and others moved quickly to get the redirect shut down. If ignore the Firefox warning to the blogspot page you get this:

Removed

However, the phishing site is still active and will probably be for awhile. Do not enter in any login credentials at any site other then twitter.com. The fake site in this case is twitter.access-logins.com/login. Note that if you take off the “login” at the end of the URL you are sent to a fake Facebook login page! Looks like these guys have been doing this for quite some time.

One interesting note about this attack…how does someone send you a DM without you following them? There was an interesting hack that is documented here that used to work, however…Twitter fixed this a few months ago. My only guess is that multiple hacked accounts were used to send legitimate DM’s. I’m not 100% sure how DM’s are being propagated in this case but it should be interesting to find out how the attack started in the coming days.

Kudos to the Twitter team and all the Twitter users that retweeted and got to word out. This alone hopefully mitigated much of the threat. I even saw in the Twitter web client that @twitter posted a warning message on the page about the threat. Great work Twitter team!

What if you gave your credentials away to this site?
Change your password immediately! Also, do you use this same password for Facebook, Myspace, email and other sites? Change those as well! Give a password manager like 1password or KeePass (KeePass is free BTW) a try to set unique passwords for every site/application you use. That way if your Twitter account did get compromised, your other accounts are safe. See this post for more information.

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What’s behind that short URL?

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plz click this short url

There was a good post over at ThreatChaos the other day about a new Firefox extension which will automatically show you the real URL’s of shortened URL’s. What is URL shortening? For example…this long URL:

http://www.google.com/maps?f=q&hl=en&geocode=&q=washington+dc&sll=37.0625,-95.677068&sspn=33.764224,56.25&ie=UTF8&ll=38.905996,-77.023773&spn=0.25915,0.439453&z=11&g=washington+dc&iwloc=addr

becomes…

http://tinyurl.com/9lum95

By using a service like Tinyurl or one of the many other sites available you can easily shorten a URL so your friends don’t freak when you send them long links. When it comes to Twitter it becomes almost mandatory that you shorten that long URL to meet the 140 character limit in your tweets.

What’s the problem?
Getting people to click on a malicious link just got easier with these services. Sure, people will still click on strange URL’s without a mask (even manually typing in strange URL’s as I showed in this post), however, by masking *any* URL with these services a phishing or malware attack can be even more successful.

Also, how can you *easily* see what the real site is behind one of these short URL’s? TinyURL and others offer you a service to “preview” URL’s but many sites don’t offer this and who is actually going to attempt to manually verify what is behind those links? That’s way too much work.

Another problem is that some of these short URL services allow you to obfuscate an already short URL with another short URL. Take for example Xrl.in. The TinyURL above (http://tinyurl.com/9lum95) becomes http://xrl.in/1b0i. This throws off the preview feature of many sites like this. This problem could add multiple redirects and levels of obfuscation to malicious links. All it takes is the right combination of short URL sites.

Right before I was about to post this I saw a post by Jennifer Leggio over at ZDNet regarding the URL redirection issue. She mentions that FriendFeed has implemented a feature that reveals short URL’s if you hover your mouse over the links. This is great…for FriendFeed, what about other more popular social media sites? Check out her article for a good overview of the issue and some interesting information about what other social media sites are doing and not doing about this problem.

The “Long URL Please” Solution
While not 100% perfect this a great start and it looks like the developer is working on improving the Firefox extension and API. You can even use it with other web browsers besides Firefox with a bookmarklet available on his site. Simply click on the bookmarklet and it will transform all the short URL’s on the web page currently loaded.

The Long URL Please Firefox extension will automatically show you the true URL of 30 supported short URL site’s. No hovering over a link or clicking to a site to preview it. It just shows you the link…no extra work on your part. This works great for the Twitter web client as well as any web page that has a link from one of the 30 supported services. One problem I saw was that short URL sites like xrl.in and others will keep popping up (I listed a site above that links 70 of these services). It’s going to take some work from the developer side to keep up with all of these new services. In addition, this doesn’t help with Twitter applications like ones that are Adobe Air based or developed using another type of framework. However, it looks like the developer is working on it and he is trying to get other applications to integrate to his API. Either way, check out this great extension and follow the developer on Twitter to get news on improvements. I look forward to see how this type of extension will evolve.

Short URL’s won’t be going anywhere soon…lets hope social media applications and end users start using them with a little bit security in mind.

What solutions do you think could solve the short URL problem?

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