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Malware in the browser: how you might get hacked by a Chrome extension

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41–50 of 64 posts

Re: Malware in the browser: how you might get hacked by a Chrome extension

#41
post #21

Earlier quoted context omitted.

I wish this was the default.

If it was, it would make Chrome all but unusable to a very large portion of its users. Once they realized Flash didn't work on any websites, they'd switch back to Internet Explorer or Firefox or Safari, rather than trying to figure out why it does that.

Technically, Flash is a plugin, not an extension.

Re: Malware in the browser: how you might get hacked by a Chrome extension

#43
post #2

The issue with Chrome extensions, just like with android apps, is that people never check the permissions and just click OK. Extensions make it even easier to install them, though, just need to redirect a user. I've also come upon some spam sites that try to get you to install extensions with annoying alerts that prevent you from closing the page, playing a recorded message "To close the page, just install the XX ext…

I do read the permissions for Android apps - they all want permissions to everything. For no good reason. Enter apathy

There is a very good reason. Apps can auto-update (the default) if they haven't added permissions over the previous versions. Consequently it is very common practise to add every permission you can conceive of using at the beginning, versus having to support a large body of users who haven't updated your app in ages.

In theory some very recent barely used newer Android version fixes this by asking for permissions at first use of them (eg first time using camera or first time accessing contacts). In practise this doesn't matter for several years.

Re: Malware in the browser: how you might get hacked by a Chrome extension

#44
Thanks for raising awareness of the possible danger of Chrome extension as a malware. I recently built my first Chrome extension and was amazed by what harm an extension could do if the maker had bad intension.

The danger is that many people do not pay much attention to the requested permissions.

To fight the issue, I think there should be a culture of open sourcing Chrome extensions. I open sourced mine, and if I build one again, I would.

Re: Malware in the browser: how you might get hacked by a Chrome extension

#45

Earlier quoted context omitted.

If it was, it would make Chrome all but unusable to a very large portion of its users. Once they realized Flash didn't work on any websites, they'd switch back to Internet Explorer or Firefox or Safari, rather than trying to figure out why it does that.

Flash is built-in to Chrome. You'll have to invent another straw man. In fact, I recommend Chrome to unsophisticated users (hi Mom!) who need access to flash content. I tell Mom to never install anything ever. (She's managed to get malware on her Mac, even though I keep reminding her not to ever click on anything that says "your computer needs updates", etc.)

But how would adblockers work if you have to whitelist a site for it to work?

Re: Malware in the browser: how you might get hacked by a Chrome extension

#46
post #35
post #6

A big problem is also with unmaintained extensions that are being bought my malicious players (or developers' accounts hijacked), which then slap on an adware script and push a new version. That way, a previously good extension with a legitimate reason for "accessing your data on all websites" can silently become malicious.

Yes. Mozilla also allows that, which is really sleazy for Mozilla.

It's a hard problem as many extensions do the equivalent of loading in a script from a remote site as part of their start -up process (consider an adblocker that regularly pulls down and updates list of ad definitions).

You could imagine that a malicious company would put through a "clean" version for testing and then once approved swap the script for the one loading malware.

Re: Malware in the browser: how you might get hacked by a Chrome extension

#47

Earlier quoted context omitted.

I remain baffled that alerts in modern browsers are still handled with an OS-level modal dialog that prevents interaction with the browser's interface elements. Couldn't the alert instead be rendered as an overlay to the page itself, be modal to just that tab, and not disable the browser Chrome? This would make it much harder for pages to "trap" users with alert spam. The existing policies (don't allow this page to c…

> Couldn't the alert instead be rendered as an overlay to the page itself, be modal to just that tab, and not disable the browser Chrome? Firefox and Safari do exactly that. > The existing policies (don't allow this page to create more dialogs -> page instantly redirects to itself to reset the flag) aren't doing a good enough job. Does that work? I've never seen any pages that circumvent alert blocking like that, and…

I don't know what the exact exploit of the behavior is, but I've observed it on several "infected" computers while working in tech support. I've seen it on Internet Explorer, Microsoft Edge, Google Chrome, and some variation of it on Safari, all of which I was only able to remedy by forcefully closing the browser using the task manager or equivalent.

Truthfully, I have not actually observed this behavior on Firefox, and I'm quite thankfully no longer in the business of providing technical support to personal computer users, so hopefully I never will.

Re: Malware in the browser: how you might get hacked by a Chrome extension

#48

Thanks for raising awareness of the possible danger of Chrome extension as a malware. I recently built my first Chrome extension and was amazed by what harm an extension could do if the maker had bad intension. The danger is that many people do not pay much attention to the requested permissions. To fight the issue, I think there should be a culture of open sourcing Chrome extensions. I open sourced mine, and if I bu…

I think it's great you did, but... People are not reading the permission request dialogs. How likely do you think it that they read the actual source? ;)

Re: Malware in the browser: how you might get hacked by a Chrome extension

#49
post #2

The issue with Chrome extensions, just like with android apps, is that people never check the permissions and just click OK. Extensions make it even easier to install them, though, just need to redirect a user. I've also come upon some spam sites that try to get you to install extensions with annoying alerts that prevent you from closing the page, playing a recorded message "To close the page, just install the XX ext…

I remain baffled that alerts in modern browsers are still handled with an OS-level modal dialog that prevents interaction with the browser's interface elements. Couldn't the alert instead be rendered as an overlay to the page itself, be modal to just that tab, and not disable the browser Chrome? This would make it much harder for pages to "trap" users with alert spam. The existing policies (don't allow this page to c…

Firefox and Safari already don't use the OS modal dialog and Chrome is working on it

https://docs.google.com/document/d/1wtV5rmLhbf1OZkbg7crtCt6h...

Re: Malware in the browser: how you might get hacked by a Chrome extension

#50
A somewhat related topic:

A few months ago Google fixed a vulnerability on the inline installation. It was possible to start a install on the attacker's website and then redirect the page to an arbitrary one. This would confuse the user, making him believe that the install came from the arbitrary page.

Here is the PoC if anyone is interested (CVE-2016-1640): https://www.youtube.com/watch?v=f_9ObDqBoo8

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