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Malvertising Campaign Infects Your Router Instead of Your Browser (bleepingcomputer.com)
An anonymous reader quotes a report from BleepingComputer: Malicious ads are serving exploit code to infect routers, instead of browsers, in order to insert ads in every site users are visiting. Unlike previous malvertising campaigns that targeted users of old Flash or Internet Explorer versions, this campaign focused on Chrome users, on both desktop and mobile devices. The malicious ads included in this malvertising campaign contain exploit code for 166 router models, which allow attackers to take over the device and insert ads on websites that didn't feature ads, or replace original ads with the attackers' own. Researchers haven't yet managed to determine an exact list of affected router models, but some of the brands targeted by the attackers include Linksys, Netgear, D-Link, Comtrend, Pirelli, and Zyxel. Because the attack is carried out via the user's browser, using strong router passwords or disabling the administration interface is not enough. The only way users can stay safe is if they update their router's firmware to the most recent versions, which most likely includes protection against the vulnerabilities used by this campaign. The "campaign" is called DNSChanger EK and works when attackers buy ads on legitimate websites and insert malicious JavaScript in these ads, "which use a WebRTC request to a Mozilla STUN server to determine the user's local IP address," according to BleepingComputer. "Based on this local IP address, the malicious code can determine if the user is on a local network managed by a small home router, and continue the attack. If this check fails, the attackers just show a random legitimate ad and move on. For the victims the crooks deem valuable, the attack chain continues. These users receive a tainted ad which redirects them to the DNSChanger EK home, where the actual exploitation begins. The next step is for the attackers to send an image file to the user's browser, which contains an AES (encryption algorithm) key embedded inside the photo using the technique of steganography. The malicious ad uses this AES key to decrypt further traffic it receives from the DNSChanger exploit kit. Crooks encrypt their operations to avoid the prying eyes of security researchers."
Better yet, I'd just say that it's your duty to use an ad blocker, mich like it was to use antivirus software in the past.
which use a WebRTC request to a Mozilla STUN server to determine the user's local IP address
Yay, more garbage Web 3.0 anti-features! In Firefox, go to about:config and set these preferences:
media.peerconnection.enabled = false
media.peerconnection.video.enabled = false
media.peerconnection.turn.disable = true
media.peerconnection.use_document_iceservers = false
"BSD: Free as in speech. Linux: Free as in beer. Windows 10: Free as in herpes." --Man On Pink Corner in #52607549.
The real question is, why do ads require fucking javascript in the first place? Limit ads to static images (JPEG, PNG) and we'll be done with all this nonsense.
That's what I'd like - an ad blocker which lets static images through but blocks any scripting or flash or other weirdness. That way instead of websites having to beg me to turn off my ad blocker, I can just tell them to find an advertiser who only serves static ads. And hopefully that would exert some pressure on the industry to abandon scripted ads in favor of static ads.
While we're at it, I'd also like a law making the ad farm serving the ads legally liable for any damages a malicious ad does. They're the ones in the best position to vet the ads before they're unleashed onto users' browsers. The lack of liability has resulted in them not giving a damn about security, and just accepting anything handed over by anyone wishing to "advertise" and adding it to their ad rotation. If they were liable, we'd probably see them morph into a self-service website where you (1) upload the JPG/GIF you wish displayed as an ad, (2) pick which tracking service you wish to use, and (3) enter the account and ad ID that the tracking service should send the ad impression info to. Don't give "advertisers" the opportunity to script their own ads, make it a cookie cutter form so there's no way to insert anything malicious.
You know a large number of commercial routers run on Linux, right? The Linux kernel isn't some magic sauce that makes you immune to hacking. On the contrary, we see flaws in programs that run on Linux all the time, these being one of them. An exploit like this can work on anything, it isn't limited just to prepackaged routers.
So what you mean is get an x64 system and run a Linux distro, with some built in tools for configuring routing. Ok... So long as it doesn't have any bugs they can exploit or check for, you are fine. If it does, well then you are back to having to update... if an update is available. A lot of the router-type Linux distros aren't very well maintained. Smoothwall, the one I hear the most crowing about, had its last release in 2014.
If you were going to point to something freely available, BSD would probably be a better bet in the form of PFSense as it is actually maintained and supported pretty well. Of course the fact that it runs on BSD is incidental to its security, it is (as best we know) secure because it has competent programmers who maintain it regularly.
However the real problem is that for many people, this is just not affordable. When you try and do all your routing and filtering in software on an x64 chip, you find you need a lot of power to push traffic. The CPUs aren't designed with routing in mind so they aren't super fast at it. PFSense needs about a 2.4GHz 4 core atom to push a gigabit of traffic, and then only if the ruleset is reasonably simple. That's about $550 for an appliance from Netgate that can do that, and that is with no wireless. Well for $180 a Netgear R7000 will push a gig of traffic no issue, and comes with a 3x3 802.11ac radio that does 2.4 and 5ghz at the same time. Likewise an EdgeRouter Lite gets a gig and is wired only for $100. They pull that off by having chips with dedicated routing logic on board.
For normal users it also needs to be easy. A suggestion of "Assemble a computer from parts, load Linux, configure routing in text files and you are good," is totally unreasonable. Even something like buying an appliance and loading code on to it from a cold state is out of reach for most people. They need a ready-made solution.