Adobe Flash Ads Launching Clipboard Hijack Attacks

bullyBEEF writes "Malicious hackers are using booby-trapped Flash banner ads to hijack clipboards for use in rogue security software attacks. In the Web attacks, which affect Mac, Windows, and Linux users running Firefox, IE, and Safari, bad guys are seizing control of the machine's clipboard (probably using the Flash command setClipboard) and inserting a hard-to-delete URL that points to a fake anti-virus program. A number of legitimate sites have been seen to host ads carrying the attack — including Newsweek, Digg, and MSNBC.com. Researcher Aviv Raff offers a harmless demo of how it's done."

Comments

what sort of flash?

[Anonymous Coward]

"Malicious hackers are using booby-trapped Flash banner ads to hijack clipboards..."

booby flash?

flashblock

[owlnation]

as though we really need yet another reason to use flashblock...

This one small piece of technology has made browsing the web bearable again. I can't ever thank its developers enough.

Re:flashblock

[enoz]

You could just create multiple profiles in Firefox, and then load the secondary profile with "-no-remote" so that it doesn't intercept any URLs or clicks that would normally load in your primary browser.

Re:flashblock

[smittyoneeach]

This is /., where over-engineering would be considered a virtue if laziness hadn't won out.

Re:flashblock

[FictionPimp]

I have talked quite a few companies out of using flash while consulting for them. I have used many legitimate reasons. Accessibility for the disabled, backwards compatibility, not using a business model dependent on a 3rd parties proprietary software, and the general annoyance of most users when they encounter a flash based website. I have found that a nice clean site developed with good web standards can do 99% of what most people want to do with flash. It will fail better on older browsers, it will load faster (in most cases), and it will be more usable by the customer with the least amount of work (larger fonts, screen readers, alternate color schemes, opening windows in new tabs, bookmarking, etc).

IMHO, companies that choose to use flash do so because they don't have the resources to see there are better choices AND they already know flash.

Re:flashblock

[FictionPimp]

I've seen good flash work. For example there was a drum kit builder I ran across where you could select drums, change colors, locations, etc. It was done really well and would of been a messy project to do with javascript. Another great example might be a 3d view of a car that lets you adjust options via a menu system.

I'm also a fan of flash games. It lowers the level of entry for game writers and performs well. However, most of the flash people want to do seems to be in places where it simply does not belong. For example site navigation, or content.

I remember trying to look up local car dealerships in my area to buy a new car. I couldn't stand how every site needed to pre-load, play music (with no option to turn off) and animate with sound every single content switch. I just wanted to look at what was on their lot, I wanted to open up the items I was interested in on separate tabs so I could compare them. The experience was so horrible I ended up just visiting the dealers (of course maybe that was their idea....)

Re:flashblock

[JayGuerette]

But, you still can't (AFAIK) run two instances of the browser running under different profiles at the same time. Sometimes it would be nice to have 2 different profiles running at the same time so you could go to sites you trust in one, and sites you don't in another.

Now, I'm perfectly willing to be told I'm wrong (in fact, if someone can I'd love to know how), but I have yet to find a way to have two profiles of Firefox running under Windows at the same time in the same Windows session.

Yes, you are completely wrong. My wife and I have discrete Firefox profiles on one computer, and often have 2 browser windows open, one on each profile. She has her own plugins, preferences, bookmarks, & history; and I have mine. Use the profile manager to create the profiles, add "-no-remote -p profilename" to a shortcut, and you're good to go. There was a plugin for FF2 called FireTitle, that allowed us to put our profile names in the window title, but alas it's not been updated for FF3.

Re:flashblock

[black_lbi]

as though we really need yet another reason to use flashblock...

I've checked the demo, and although the flash is blocked, it initially modifies my clipboard content. But I can use ctrl-c to replace it with something else. If the flash isn't blocked, ctrl-c is useless.
So flashblock kinda helps you, but you're still vulnerable.

confirmed on mac os x 10.5.4

[v1]

it copied "http://www.evil.com/ to my clipboard. Any app I pasted into pasted that url. I tried many apps to copy something to the clipboard but it remained evil.

The article says in one place you have to restart, and in another you have to close your browser window. I found that closing safari was not sufficient, and I had to quit safari to successfully copy different data into my clipboard with other apps.

Re:confirmed on mac os x 10.5.4

[ScentCone]

confirmed on mac os x 10.5.4

I'm sorry, but you're using a Mac and anything like this is completely impossible. Why do you hate Mac users, that you would say such a disturbing thing? You are mean.

Re:confirmed on mac os x 10.5.4

[Mr. Marabou Man]

Yeah ? Interesting. On my setups (Firefox 3.0.1 on Slackware & Tiger, Safari 3.1.2 on Tiger), closing the tab is sufficient to make it go away. YMMV, obviously.

Re:confirmed on mac os x 10.5.4

[fluffman86]

ditto. closing the tab in firefox 3.0.1 on Ubuntu 8.04 works for me.

Write Filter = Best Antivirus

[Z34107]

Good thing my laptop runs EWF drivers. Any changes made to the C volume (a solid state drive) made in memory instead. Everything works like you'd expect it to - delete a file and it's gone - until you reboot, that is, and all of your in-memory changes are discarded.

I'd like to see XP Antivirus Pro 2008 thoroughly embed its tendrils... and then survive a restart. No changes are committed unless I manually force it.

Considering that Circuit City will sell you a PC with 6 GB of RAM for $999, I wonder why EWF isn't a standard feature. Probably because somebody would forget that defragging your hard disk would exhaust available RAM and then die, or wonder where that program they just installed went after they rebooted...

Linux has a similar filesystem, I believe it's used for boot CDs. It pairs the read-only volume with a RAM drive, and all writes are cached there and discarded.

Re:Write Filter = Best Antivirus

[WK2]

So, basically, writing to your hard drive is twice as hard as it is on a normal computer? And you call that a feature that should be installed by default?

Your original problem is that have programs installed that do stuff to your computer that you don't want. And your solution is an extra layer that those programs are not designed to penetrate. There are two problems with having such software installed by default:
a) it would be twice as hard to do stuff. I'm sure you realize this, and have already gotten used to it, and accept it.
b) if this software became popular, then any malicious, or just poorly behaved software that does stuff you don't want, such as write to the hard disk, will write to the hard disk as normal, and then penetrate your extra layer of obscurity to actually write to the hard disk. Programmers would be somewhat inconvenienced, and would have to use special libraries for writing to the hard disk, and users would be annoyed.

This EWF software you speak of is for a niche market, and would fail for everybody if it became popular. It's sort of how Linux doesn't have many viruses. Except Linux not having viruses is a side effect, and there are plenty of other reasons to use Linux if it became popular and malware authors decided to target it, whereas your software would fail if it became popular, and malware authors targetted it.

It's kind of like how the Windows outgoing firewall is useless. Every piece of malware knows to put themselves on that whitelist. Whereas if you use a software firewall that is not installed by default, then chances are good that the malware author didn't spend time on bypassing that one.

Shockwave...

[azav]

I'll bet you can do it too in Shockwave with copyToClipboard. It is a little trickier though as copytoClipboard holds the reference to the Director member copied IIRC. Thinking about it, any web service that supports the clipboard should be able to do this.

How to fix this:

[MrMista_B]

http://adblockplus.org/en/

Problem solved!

Seriously, blocking ads and javascript and flash stuff is like a game for me now, I get a little thrill of victory every time I block one of those things, it's great.

Re:How to fix this:

[AceofSpades19]

You have problems....

Re:Yes, its annoying

[QuantumG]

Umm.. yeah, and then you'll say "sure, install this program I didn't even ask to install". If that's something to be worried about then no amount of "security" is going to protect these people.

Lame results with Linux

[keeboo]

Well I accessed the page under Linux and Firefox 2 and the following things happened:

The middle mouse button pastes as usual.
The hijacked content only appeared with CTRL-V.

All I need to do is to close the page tab and it's gone.

Disappointing.

Re:Yes, its annoying

[slashqwerty]

But I fail to see how you can leverage this to gain privs.

I suppose it would be possible to populate the clipboard with corrupted contents, perhaps a string of XML that another app would try to consume. If that other app, designed strictly for desktop use, has a vulnerability in the way it processes said XML an attacker may be able to gain privileges. It's possible such an app will examine the clipboard contents just to determine if it should enable the Paste menu. Which means you could be vulnerable even though you never paste from the clipboard.

Not affected it seems ...

[YeeHaW_Jelte]

... on this old system with SuSE 9.1, FF 2.0.014, flash 7.

Hoorah for lazy upgrading ;)

Re:It may not be this

[riceboy50]

If you are using FF3 and beta Firebug, then you are probably seeing the DOM corruption bug that I see when ads are inserting into the DOM. The symptom is that the whole page disappears except for that ad. I've seen this behavior on several sites, including /. I haven't figured out a remedy yet except to disable Firebug, and we all know that's not going to happen!

Re:Hard to remove?

[INeededALogin]

I closed the demo window

The average user is not going to know that they have been hijacked and they won't necessarily know which window is doing it. The clipboard hijacker could even wait until you copy a url before modifying it.

Re:What about Opera?

[hellwig]

Tried with Opera 9.51 on gOs/Ubuntu 7.10 and it did copy the url to my clipboard which I was unable to replace (with ctrl+c) until I closed the tab. After closure, I regained control of my clipboard.

I tried using a user javascript file that would block all flash content and allow me to individually activate the various flash files, but I had problems with things like YouTube, and eventually I abandoned it when certain websites I frequented used Flash for the most obsurd reasons (don't remember which, this was over a year ago). Might be worthwhile to bring it back.

Whew.

[rascher]

Its about time they start making software that runs on Linux too.

Re:Clicked on the flash area in NoScript in the de

[unlametheweak]

These days you have to go out of your way to avoid flash by learning about and installing less popular Web browsers like Firefox and installing extensions (Add-ons) like NoScript that you have to educate yourself about. These days even browsers like Firefox come pre-installed with crapware and bloatware like Microsoft DRM and Shockwave Flash. These things I have manually disabled.

I often hear people on Slashdot claiming that Flash is safe, but I also constantly hear about flash-based exploits as well. To most Slashdot users I would think Flash would be relatively safe, however most people are not Slashdot users.

The Internet is becoming less accessible to me as the years go by. There is no need for Flash or Java or JavaScript (to navigate to a URL for example). I can only perceive malicious reasons why Web developers would try to force people to use these technologies.

When a Web site says Flash, JavaScript, Silverlight, Internet Explorer or anything else is required then that Website is never again visited. One must separate the wheat from the chaff.

Just a loop

[Twillerror]

Okay so the flash ad just copies something to the clipboard in a loop. Closing the tab or browser stops this. I suppose if you are running your browser in the background this would be very annoying and you wouldn't know.

Today firefox and IE prompt if you want to use the clipboard from javascript, but it used to not be this way. I'm sure Adobe will patch this soon enough.

This is like old popups...and oversight that is being exploited by the annoying "internet bully". It's like getting a wet willing or you head stuffed in a toilet.

The issue is here that both Flash and the underlying operating system don't have any kind of cut and paste protection. X, Mac OS X, and XP/Vista should not allow a program to copy and paste the same dam string to the clipboard over and over. Really kind of annoying that we have to spend so many human hours fixing "problems" like this...but such is life I suppose.

Re:Yes, its annoying

[jesser]

But I fail to see how you can leverage this to gain privs.

1. Every 100ms, put some evil UNIX commands on the clipboard, surrounded by line breaks. I'm sure you can come up with a one-liner that compromises a user's system.

2. Hope someone will paste into a Terminal window while your evil page is open.

I paste into Terminal windows all the time. For example, I might copy an error message and then grep another file for the message. If there's an evil web page open while I do that, the paste will own me.

Secure Linux Clipboards

[Doc Ruby]

So now it seems that Linux's nonintegrated multiple clipboards and their UIs (Ctrl-c, and select/middle-click) are a security feature, not a bug.

Re:Clicked on the flash area in NoScript in the de

[Hurricane78]

> When a Web site says Flash, JavaScript, Silverlight, Internet Explorer or anything else is required then that Website is never again visited. One must separate the wheat from the chaff.

This maybe is true, except if you want to do a real web application. Loading a whole HTML-page, just to change some state of an (non-form-element) interface element... That's insanity.
You've done the same that someone in a trauma does. You're created false associations. It's not the technology or even the virtual machine that's bad. It's the implementation.
Your argument is the same, as if someone who had only bad experiences with x86, while having good ones with his old 86000s, argues that "if an application requires x86, then that application is never again used."
The same is true for OSes. Someone could implement Windows XP in a proper manner, and make it a very safe system. (I did not say that someone would want, tough ;)

Or in short:
Someone can crack a bad JavaScript VM and contaminate the rest of the system. And someone could crack a bad OS, and contaminate the rest of the system. There are even examples for this on virtualization VMs. (Heck, the system's clipboard is accessible to all 3 of them, on modern VMs!)

So my vote goes for Replacing the JavaScript VM with a hardened generic VM, with a fixed interface to the outside world, and adding JavaScript, Python, Ruby, Haskel, Ocaml and more as languages to it (via add-ons, or pre-compiled?)

Okay, I think one should remove at least one layer of abstraction/VM and harden the OS so that even OpenGL on JavaScript would not have a performance loss. (Yes, this would be useful. Eg. for quick dynamic data visualization or entertainment applications.)

Re:Clicked on the flash area in NoScript in the de

[Daengbo]

I just use SWFDec. It avoids the Flash problem by failing to play about 50% of the stuff out there.

The demo hijack page doesn't work, either. Surprise!

Just kidding. I like SWFDec much better than Flash + nspluginwrapper on my 64-bit Lenny.

Re:Clicked on the flash area in NoScript in the de

[negRo_slim]

I often hear people on Slashdot claiming that Flash is safe

Well sir you must view /. at a much lower threshold then I do!

Re:Go tell Adobe

[MightyMartian]

After a decade of horrors visited upon the world by Internet Explorer, you'd think everyone would view such a large proportion of content being delivered via a proprietary format and software (one, mind you, that renders via software and doesn't even have a functioning 64 bit version) as so incredibly dangerous and foolish as to dismiss it.

If just as much effort were put into a better streamlined and functional Javascript/ECMAscript interpreter based on open specs as is being put into reverse engineering Flash and now trying to figure out ways to secure it, we wouldn't even need the goddamn thing to begin with. There are better scripting engines than flash, there are better video formats than Flash, so why the fuck is so much attention paid to something that's so inherently flawed?

Re:Clicked on the flash area in NoScript in the de

[jacquesm]

Worked here as well. One more point against flash, what on *earth* were they thinking when they put that 'feature' in there ?