Spyware Disguises Itself as Firefox Extension

Juha-Matti Laurio writes "The antivirus specialists at McAfee have warned of a Trojan that disguises itself as a Firefox extension. The trojan installs itself as a Firefox extension, presenting itself as a legitimate existing extension called numberedlinks. It then begins intercepting passwords and credit card numbers entered into the browser, which it then sends to an external server. The most dangerous part of the issue is that it records itself directly into the Firefox configuration data, avoiding the regular installation and confirmation process."

Comments

Not a vulnerability.

[Short Circuit]

Note that this isn't a Firefox vulnerability.

The trojan is opened as a Windows executable from email attachments, and writes itself into the Firefox profile's configuration directory.

Re:Not a vulnerability.

[kfg]

I refuse to use this trojan until it's ported to Linux.

We have to send a message to developers that we want our apps native.

KFG

Re:Not a vulnerability.

[kfg]

McAfee do not describe it as a Firefox exploit. They describe it as a VBS exploit originally written to target IE, i.e., a Windows exploit.

KFG

Re:Not a vulnerability.

[greed]

While true, perhaps a related problem that actually is a vulnerability is the fact that Firefox (apparently) only checks for a valid signature on the plugin at download/install time. Maybe the Firefox configuration file, or at the very least the binaries for each extension, should be cryptographically verified at runtime.

Once someone's system is compromised, they can replace or alter the FireFox binary which verifies the signatures, replace libnssckbi.so, libsoftokn3.so, whatever.

You can't win at that point. If you're storing your operating system and executables on writable media, it can never be trusted to that level. The hardware would have to cryptographically verify the boot loader on disk, which would verify the kernel, which would then be able to verify everything it executes--FireFox alone can't do it.

(Say, what was that hardware-based Trusted Computing stuff supposed to do? In addition to ramming DRM down everyone's PCI bus, wasn't there system verification too?)

Re:Not a vulnerability.

[140Mandak262Jamuna]

Come on, You dont even have to be a script kiddie to write malware for Linux.

This is how it works:

First create an executable that will do bad things. It could even be a csh script. Then send emails to all and sundry like this and attach that file"

Dear Linuxuser,

This is a virus/trojan/worm/malware for Linux. It works on the honor system. Please forward the attachment to all addresses in your .mailrc first and then save it to disk, chmod +x and sudo it. Thank you.

Attachment: malware

Re:Not a vulnerability.

[zo1dberg]

This is the one thing that keeps people from running Linux on their desktops! We normal users don't want to fiddle around with the commandline and stuff like that, we need a point-and-click-interface to compromise the security of our computers! Trust me, until this is fixed, Linux has no hope of ever becoming a serious competitor to Windows.

Re:Not a vulnerability.

[Not The Real Me]

Good point.

A friend of mine has certifications as an MCSE and a CNE. When I tell him to run "ipconfig /all" and "route print" (on his WinXP machine), the look of consternation and confusion on his face is priceless.

Re:Not a vulnerability.

[PsychoSid]

csh ! What century have I entered this time.

MozillaZine Has More

[Anonymous Coward]

This MozillaZine article has lots more on the trogan horse, including instructions for spotting if you have it.

Break extension

[Anonymous Coward]

In next version of Firefox, the extension will be broken anyways. Mozilla breaks extension every new release. :D

Thankfully, I'm running IE

[Anonymous Coward]

Which makes me invulnerable to snooping for credit card numbers as all my accounts are empty and my credit rating is ruined.

Spyware Disguised as an MSIE Extension

[krell]

It could have been worse, like spyware disguised as a Microsoft Internet Explorer extension. That's sort of like Nixon wearing a Nixon mask.

RTFA

[sensei85]

Again with people jumping to conclusions. The trojan is loaded when you open an .exe attached to an e-mail from "Wal-mart". Lesson to be learned: never open random .exe attachments. Ever. Problem solved.

For those of you screaming that "numberedlinks" should be removed from the mozilla site, that wouldn't fix the problem. The original extension is perfectly safe and NOT a trojan. This one is just spoofing it by installing itself with the same name.

A little more careful reading and some common sense go a long way

RE: Emphasis on that.

[KURAAKU Deibiddo]

Actually, if you read the article more closely (and similar articles that have appeared in no shortage of other places), the malware pretends to be the numberdlinks extension. Your post implies that the actual extension is malware, and this is untrue.

Additionally, if you read the Slashdot blurb, it's explained pretty clearly there.

Basically, if you click on e-mail attachments without knowing what they are, it's your own fault if your computer becomes infested with viruses and spyware.

Re:Emphasis on that.

[dedazo]

This is an Outlook/IE "virus" who's payload is a keylogger and crap that hooks into Firefox.

This is an user-executed email attachment with a trojan. It will happily be executed from Outlook Express, IE, Eudora and Thunderbird. McAfee mentions they've seen one version trying to exploit a three year old IE vulnerability. If you haven't patched that, well then you deserve to get nailed.

This does not exploit any vulnerability in Firefox

It is a vulnerability in that FF will happily load and execute any plugins dropped into its profile directory. The only time you are warned about installing someone is at download time. FF will never check for a signature or otherwise go "oh, a new plugin I've never seen. Hmmm, maybe I should ask the user about it?". Vulnerability.

If your OS is not secure, no app running on it can be secured.

If your OS is being operated by a user that executes attachments from "WalMart" that read "helo, teh attcachements for yuo pleasures" then your OS is not secure.

BTW, this progression is interesting. When FF came out just installing it would make the world safe, because it was invulnerable and impervious. Now I also have to switch operating systems? And when someone finds another exploit in SSH

make it open source

[kdemetter]

just send the source code in a nice tarball .

that way it's open source and people can improve it .

Re: Emphasis on that.

[PhoenixPath]

No. It's not.

Any extension downloaded from addons.mozilla.org has been tested, is widely used, and subject to an enormous amount of user feedback.

Now, if you download an extension from kickme.to/malware, you get what you deserve.

Re:Emphasis on that.

[mrchaotica]

It is a vulnerability in that FF will happily load and execute any plugins dropped into its profile directory. The only time you are warned about installing someone is at download time. FF will never check for a signature or otherwise go "oh, a new plugin I've never seen. Hmmm, maybe I should ask the user about it?". Vulnerability.

Okay, and then the next trojan will simply add itself to the file that Firefox checks to see if the extension is new, and you're back to square one.

Firefox isn't the problem. The fact that the thing can write to the application's directory means the computer is already compromised.