Conducting Password Splicing Attacks With oclHashcat-plus
2012-01-19 00:01:12 by chort
A coworker once told me he imagined immigration officials handing Chinese immigrants two bags with slips of paper, asking them to pick a paper from each bag and put them together to form the name of their restaurant. This is how he imagined names like "Green Dragon," or "Golden Lotus," or "China Garden" got created. While it might not be a very accurate way to describe culinary establishment marketing, it is similar to how many users choose passwords. I'm calling this method the "Chinese Take-out Attack."
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Free Advice for the DHS
2012-01-17 10:46:51 by chort
You may be aware that the DHS are now sending (opt-in) "Daily Cyber Reports" to IT and security practitioners. The stated purpose of the reports is "to facilitate a greater understanding of the nature and scope of threats to the homeland." I wonder if they're aware of the threat they're creating by teaching people to open PDF documents from unauthenticated email? Well they have no excuse now, because I told them. Here's a copy of the email I sent them on the topic.
1.) Create a DKIM record for hq.dhs.gov and use it to sign the headers of the email, so recipients can verify it was really sent by hq.dhs.gov, rather than a phishing site.
2.) Publish a public key for OSINTBranchMailbox [at] hq.dhs.gov on a website that has a DNSSEC-signed record.
3.) Use the private key (GPG or S/MIME) to sign messages sent from OSINTBranchMailbox [at] hq.dhs.gov
4.) DO NOT INCLUDE ATTACHMENTS, unless they are plain text. Training users to open Adobe and Microsoft documents is the worst thing you can do, when most compromises are initiated with poisoned Adobe or Microsoft documents.
5.) Host the Cyber Report on a website that has a DNSSEC-signed DNS record and an SSL certificate that matches the hostname of the website and chains up to a trusted root.
If you're going to advise organizations on security, you should secure your infrastructure and comms too. Lead through action.
PS you haven't configured your authoritative DNS server properly. The template default value for email address is showing in the SOA.
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Simple Guide to Secure Anything
2012-01-02 23:28:32 by chort
Recently I was asked for some pointers on creating a security roadmap. Since there's no one-size-fits-all strategy for which programs or technologies to implement, this is a tough question to answer. After thinking about it for a few minutes, I stepped back and put together this abstract, which is really what security boils down to after all. The rest is implementation details.
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Notes on GPU-based Hash Computation
2011-10-29 16:03:45 by chort
In the last few weeks I've learned a lot about applying GPUs to break password hashes. I'd like to thank @ErrataRob for writing the blog post that got me started in this field. If you haven't read Rob's post, I highly recommend you do that first, because this post builds on it. Don't buy a graphics card until you've read my post though, because there are some important updates.
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Lulzsec, Lies, and the Call to Wake
2011-06-27 00:03:05 by chort
For the past 50 days LulzSec has captured the attention of the information security community, the mainstream media, and just about every other kind of media. Has anyone stopped to wonder what it is that causes the LulzSec saga to be so "sticky?"
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Cyberwars are real, but not what you think
2011-05-26 14:08:33 by chort
It struck me today that events are in motion for unavoidable cyber-conflicts. This statement won't shock anyone, since sensationalists have been predicting "a digital Pearl Harbor" for years. I don't agree with the predictions. In fact, I don't think it's likely that any warfare-like confrontations between nation states in cyberspace will happen in the near future. Sure there's rampant electronic espionage, but that hardly counts as warfare.
I think we're already seeing the beginning skirmishes in far more important events. We've seen protestors in various oppressed countries fighting to circumvent filtering and outright disconnection. We've seen massive DDoS attacks against draconian "Big Content" companies in retaliation for their heavy-handed treatment of their own customers. We've seen resourceful people overcome collateral damage caused by clumsy and ignorant government attempts to censor the Internet right here in the United States.
I don't see these events as anomalies or outliers. I see them as precursors. I think there's a strong undercurrent of opposition to the increasing attempts by governments and extremely large corporations to infringe on individual rights. In spite of that, It seems executives of these corporations are determined to forge ahead with rights-trampling legislation to restrict how individuals can access the Internet.
So what happens when out-of-touch elites try to enforce their will on the vast unwashed masses? That's when you get cyberwar. The people enacting new surveillance and censorship measures are forgetting that digital is the great equalizer. Any kid with a $200 laptop can take down a multi-billion dollar corporation. The more laws Big Content lobbyists have passed to make life miserable for average citizens, the more Anonymous* members they are going to create. It's difficult, although not impossible (as dramatically shown in the middle east this year) to physically resist power. To digitally resist power is nearly effortless. Those in favor of extreme enforcement of content "rights" are picking a fight they cannot reasonably be expected to win. The only question is how long it will take them to lose.
*To be clear, I'm not now, nor do I ever plan on being a member of Anonymous.
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What if We Have the RSA Token Threat Backwards
2011-04-18 22:59:03 by chort
Thus far, all the speculation I've seen regarding the RSA SecurID breach centered on speculation that if attackers could somehow discover the serial numbers of tokens in use, they could derive the seed and whittle it down to 1-factor authentication. The advice from RSA certainly lends credibility to that theory, since they're essentially telling customers to double the length of the PINs in use, exponentially increasing the difficulty of guessing that factor.
If we accept the claim (and I am not suggesting we should merely for being asked to) by RSA that the attack was sponsored by an arm of the Chinese Communist government (let's drop the diplomatic "APT" BS), then perhaps there is another threat vector we haven't considered. As we know, plenty of counterfeit gear is manufactured in China. There is also speculation that what was stolen was not the seed database itself, but the serial-to-seed mapping algorithm. Imagine if they were able to create knock-off SecurID tokens that actually worked, then pollute the supply chain through resellers, and have them end up in organizations that are later targeted for break-ins.
It's clear from past behavior, the Chinese government and/or military are willing to take the long view on industrial espionage. I'm sure they wouldn't mind waiting for this gear to infiltrate high-value organizations. Besides, imagine if they added a few "bonus" features to the tokens, such as cellular radios, and microphones.
No, I don't have any inside information, this is all speculation on my part. This is just an angle I haven't heard anyone mention yet.
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Integrating PF with Fail2ban 0.9
2011-03-20 20:27:04 by chort
Many security practitioners are familiar with Fail2ban, an application that scans log files for various types of suspicious failures and bans the source IP after too many attempts. Most users implement it to protect their Linux systems (via Netfilter/iptables and TCP wrappers), but it also includes methods for Sendmail and IPFW (FreeBSD and OSX).
What is notably missing from the above list is the wildly popular PF (Packet Filter). It was originally designed by Daniel Hartmeier to replace IPF in OpenBSD, but has since been adopted by FreeBSD, NetBSD, and DragonflyBSD. PF is widely embraced due to the simplicity and clarity of the syntax, and the comprehensive array of professional-grade features available.
Ironically, PF is probably better known now due to FreeBSD than the originating project, OpenBSD. It's somewhat startling that no one has yet included PF support in Fail2ban. It's also disappointing that Apple hasn't switch from IPFW to PF as their packet filtering firewall (hint hint).
In the spirit of the Open Source "submit a patch or GTFO" mentality, here's how you can use Fail2ban to insert rules into your PF firewall.
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Unauthenticated SSL Sends a Dangerous Message
2011-03-05 16:45:30 by chort
Recently I decided to write an application for Twitter to report changes in my friends and followers. As part of the process I went looking for a pre-built library of methods that I could use to interact with the Twitter API. I settled on python-twitter as an actively-developed solution that should keep up with changes to the API.
Due to Twitter's rocky past with SSL/TLS (henceforth simply SSL) support on their web interface, I decided it would be prudent to investigate whether their API used SSL. It turns out that it does, and it has a properly signed certificate. Then I looked at twitter-python to see if it had and option to connect over SSL, and was pleased to notice that it does by default. On a hunch I checked out the underlying library that python-twitter is using to make HTTP requests, and I was shocked at what I found.
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Stop Trying to Prevent Break-ins
2011-02-20 14:55:29 by chort
Ready for a shocker? You shouldn't be spending all those resources trying to shore-up your network against attacks. It sounds insane, but this is the conclusion I've reached after spending a week talking to some of the best and brightest minds in Information Security.
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BsidesSF 2011
2011-02-19 21:07:55 by chort
I just took 3 days off from work to attend BSidesSF and the Barracuda Networks Security Wine-out, with an interlude to work the RSA Conference. The following is a rambling summary of the topics and ideas I encountered this week, along with my commentary.
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My Complaint Letter to the TSA
2010-11-23 15:45:54 by chort
Surrendering my 4th amendment rights should not be a condition of travel within the United States.
With strengthening of cockpit doors and revised flight procedures to restrict cockpit access, the likelihood of a hijacking being leveraged to use an aircraft as a weapon has been drastically reduced. Couple that with passengers' realization that compliance with terrorists is not in their best interest, the probability of any future airline attack causing more casualties than the passengers and crew on board is near nil.
This means that airplanes are not unique from sports stadiums, shopping malls, trains, buses, subways, cinemas, or scores of other kinds venues where inflicting hundreds of casualties is possible.
We cannot create a police state where every citizen must be viewed naked or sexually groped in order to venture into public places. Stop the Security Theater with airplanes and the inconvenience to millions of people who must fly for their jobs every week.
Sincerely,
Brian Keefer
You may send your own complaint to the TSA here.
PS Of the last 3 terrorist attempts vs. aircraft going to the United States, only 67% were against passenger planes, none of them were hijackings, and none of them went through TSA security. Given those facts, do you really think drastic and invasive escalations against US citizens are necessary?
Update: Thanks to @georgevhulme for pointing out several typos. Also thanks to @mckeay for reminding me that money talks--I've stopped flying short trips (as of last year) due to TSA hassles, and have been driving instead. That takes money away from airlines, pollutes more, and (statistically speaking) causes more deaths. How is this "security" helping again?
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If I Were a CSO pt1
2010-11-17 11:59:28 by chort
If I were a CSO, I'd go to firms like Securosis for analysis. Why? Because they have a no BS approach. They call out vendors for bogus claims and useless products. People who have been in the security field for a long time and have really looked critically at enterprises and vendors can spot regurgitated marketing spin a mile off. We can also tell when advice being given has no foundation in actual experience.
It seems like the vast majority of "analysis" is simply an indicator of herd mentality. I don't want to know what a bunch of people with no idea are doing; I want to know what intelligent and measurably successful people are doing. The "conventional wisdom" is often wrong. The "best practices" are rarely updated, and usually only with additions of new practices, not subtractions of outdated practices.
That sentiment is echoed by few analysts outside of Securosis, but one of them is Josh Corman from The 451 Group (which has recently hired a few common-sense folks to fill out their ranks). I'm not familiar with The 451 Group's work, but if their hiring practices are any indication (in addition to Corman, they've also picked up Wendy Nather) it's probably solid.
It's about time people started applying healthy skepticism and subject-matter expertise, rather than the modern-day version of "nobody got fired for buying IBM".
If you want to follow the Securosis guys on Twitter they are (in part): Rich Mogull, Mike Rothman, Adrian Lane, and David Mortman.
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Striking a Balance on Airport Security
2010-11-16 23:44:30 by chort
There has been a lot of press and grass-roots coverage of the TSA recently, specifically revolving around the increased usage of backscatter x-ray devices and more invasive physical inspections. Various DHS and TSA officials have made statements to the effect that they're sympathetic to the complaints, but the new measures are "necessary" and they're "striking a balance" between constitutional rights and security.
When I hear someone say "strike a balance" I visualize a see-saw, or a scale of justice, where the two sides are equally weighted in order to balance them. If we were to take the comments by Janet Napolitano and John Pistole at face value, we might reasonably think they're trying to find a middle ground somewhere between completely acceptable (say, passing through a magnetometer) and totally unacceptable (like cavity searches). The problem is that there is no balance. The scale is so far tilted to the side of violating constitutional rights that even a former Director of TSA Security Operations, Mo McGowan, actually admitted these measures violate the 4th amendment.
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The Problems in Certifying Software Safety
2010-11-03 14:38:57 by chort
I just finished reading @TanAtHNN's 1999 paper contrasting inspection of electrical devices and safes with software and information security products (thanks toJosh Corman for brining it up). The paper pointed out failings of prominent technology associations in the area of certification, and indicated encryption standards (such as FIPS) as examples of how it could be done right.
Overall I think the paper raises good questions. I think you would be hard-pressed to find people in the industry (especially security researchers) who don't think companies should be held to a higher-than-current standard for information technology. I believe the paper comes up a bit short, however in recognizing the differences between physical productions and digital products.
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Many security policies are a waste of time
2010-04-14 07:57:07 by chort
Ready for a shocker? A lot of the things your IT/Security department makes you do are stupid. According to Microsoft researcher Cormac Herley quoted in The Boston Globe, many "common sense" security practices are economically unwise. In plain English: You lose more money following a lot of security recommendations than you would by just letting the bad thing happen and dealing with the aftermath.
To continue, flip over the keyboard and read the sticky note...
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Dear Apple: Please QA Parental Controls for OS X Apps
2010-04-13 20:12:06 by chort
As many people know, Apple introduced Parental Controls in Tiger. The current version in Snow Leopard allows administrators to block potentially inappropriate content, specific sites, and access to unapproved applications.
The first two work more or less how you would expect (although the error message when a site is blocked for content has been bewildering in my experience), but the application ACLs are a disaster. They prevent the application from being run if it's not approved for that user (in fact, with Simple Finder enabled you can't even see it), but it's when you try to allow a restricted user to access an application that the fun starts.
I haven't examined it in depth, but it appears that OS X adds some kind of wrapper or extended attribute to an application when you enabled a restricted user to run it. The problem is that this extra layer is extremely invasive, and most of the apps I've tried to use it with simply crash. Not only do the crash for the restricted user, but they also crash for unrestricted users. It's demonstrably the Parental Controls that cause this problem, because if you Trash the app and reinstall it, leaving Parental Controls alone, the app will run fine for unrestricted users.
Parental Controls have been around since Tiger, and this problem existed for sure in Leopard (possibly Tiger, I forget when I started using the feature) and definitely still exists in Snow Leopard. So I have a simple question for Apple: Did you bother to QA this feature at all? I know I've submitted the automated reports at least a few times after OS X detected an app crash and it does include audit trail information showing that Parental Control attributes were changed for the app prior to it crashing.
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Time for Apple to care about security
2010-03-25 14:59:39 by chort
Apple's operating system has long been considered a refuge for those sick of viruses and malware that plague Windows systems, but this reputation for safety has been widely misinterpreted to mean the design is safe. In fact, as has been widely recognized in the security community, it's the relative rarity of Apple machines on networks that simply makes them an economically uninteresting target.
Apple for their part have enthusiastically encouraged this misconception, and while they've benefited from the positive PR, they haven't actually taken the concept of safety to heart. Much like the corporation in Redmond that they delight so much in mocking, they seem determined to ignore security issues until they affect public perception.
Read on for the ownage ->
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Blogs attract PHP scans
2010-01-24 23:54:49 by chort
I've been noticing that since I put up this blog I've been getting scans for common PHP files/site layouts. This is interesting because my main site hasn't been scanned for them at all during the same time period.
I also noticed that the majority of the spider traffic to my blog is from Baidu, in contrast with the rest of my site.
I had forgotten how fun it is to scan my webserver logs for patterns.
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