Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Multiple Russia-aligned threat actors actively targeting Signal Messenger

cloud.google.com

Post reply on HN
Print view View original

171–180 of 329 posts

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#171

Post by mmooss »

BrenBarn wrote: post #166

Is this suggesting that a single QR scan can on its own perform the device linking? If so, it seems like that's kind of the hole here, right? Like you shouldn't be able to scan a code that on its own links the device; you should have to manually confirm with like "Yes I want to link to this device". And then if you thought you were scanning a group invite code you'd realize you weren't. (Yeah, you'd still have to rea…

> you should have to manually confirm with like "Yes I want to link to this device". And then if you thought you were scanning a group invite code you'd realize you weren't. (Yeah, you'd still have to realize that, but I think it's a meaningful step up over just "you scanned a code to join a group and instead it silently linked a different device".)

Remember that Signal is designed for non-technical users. Many/most do not understand QR codes, links, linking, etc, and they do not think much about it. They take an immediate, instinctive guess and click on something - often to get it off the screen so they can go back to what they were doing.

Do you have reason to think there is not confirmation? Maybe Signal's documentation will tell you.

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#172

Post by autoexec »

h4ck_th3_pl4n3t wrote: post #106
autoexec wrote: post #75

Earlier quoted context omitted.

If you're a signal user and didn't know about this already, that should tell you everything you need to know about signal. See https://community.signalusers.org/t/proper-secure-value-secu... Then read the first line of their terms and privacy policy page which says: "Signal is designed to never collect or store any sensitive information." ( https://signal.org/legal/ ) Signal loves to brag about the times when the gov…

I wanted to add that there is the cease and desist case against Signal-FOSS fork that tried to implement an open server, too. In my opinion Briar is where it's at, but because there's no data collection it's pain to do a handshake or manage contacts.

Signal-FOSS is still around right? Got a link to some of the drama? I'm curious to see what their grounds were. Did they just object to the use of their name?

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#174

Post by vlovich123 »

diputsmonro wrote: post #101
vetrom wrote: post #40

Signal (and basically any app) with a linked devices workflow has been risky for awhile now. I touched on this last year ( https://news.ycombinator.com/context?id=40303736 ) when Telegram was trash talking Signal -- and its implementation of linked devices has been problematic for a long time: https://eprint.iacr.org/2021/626.pdf . I'm only surprised it took this long for an in-the-wild attack to appear in open liter…

If I'm reading that right, the attack assumes the attacker has (among other things) a private key (IK) stored only on the user's device, and the user's password. Thus, engaging on this attack would seem to require hardware access to one of the victims' devices (or some other backdoor), in which case you've already lost. Correct me if I'm wrong, but that doesn't seem particularly dangerous to me? As always, security o…

It sounds like all that's needed is a device that had been linked in the past. Unlinking doesn't have the security requirements you'd think it would and there's a phishing attack to make scanning a QR code trigger a device link (which seems really really bad if the user doesn't even have to take much action)

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#175

Post by motorest »

dmix wrote: post #105
newsclues wrote: post #61

Earlier quoted context omitted.

Phones aren’t secure but are more secure than the standard radios most have access to. Encrypted milspec comms aren’t the standard in a massive war. It’s weird but discord, signal and some mapping apps on smartphones are how this war is being fought.

Russians aren't allowed to bring phones on the frontlines apparently but Ukranians often do still as they have the combat management app which is critical to operations. I've always wondered if this is why there's far more published footage of Ukranian combat video than Russian. Beyond the donation incentive they attached to videos when publishing them on Youtube/Telegram.

> I've always wondered if this is why there's far more published footage of Ukranian combat video than Russian.

I'm sure Russia's meat wave tactics have more of a role. If you're sending your troops in suicide missions, including guys without weapons and even in crutches, you're not exactly too keen in having them carrying mobile phones to document the experience or even, heavens forbid, survive by surrendering.

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#176

Post by morkalork »

davidw wrote: post #153
4ndrewl wrote: post #119

"Russia-aligned threat actors" has a whole new meaning this last week.

I wonder if someone in the US will declare that, actually, Signal is actively targeting the Russia-aligned threat actors.

Or that Signal shouldn't have started it in the first place

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#178

Post by tremon »

ycombinatrix wrote: post #26
golergka wrote: post #15

Earlier quoted context omitted.

What if you need to contact someone and they use whatsapp?

Not GP - I tolerate Whatsapp but I draw the line at SMS.

For me it's the other way around: I tolerate SMS but I draw the line at Whatsapp.

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#179

Post by mmooss »

josh2600 wrote: post #151

There are many voices which try to tell you that signal is compromised. Notice that all of those voices have less open-source-ness than Signal in virtually all cases. Signal is doing its best to be a web scale company and also defend human rights. Individual dignity matters. This is not a simple conversation.

Also, it's a tricky environment of disinformation generally, and in particular for anything valuable like Signal. If Signal is secure, attackers on privacy would want people to believe Signal is compromised and to use something else. If it's not, then they would want people to believe Signal is secure.

I think the solution is to completely ignore any potential disinfo source, especially random people on social media (including HN). It's hard to do when that's where the social center is - you have to exclude yourself. Restrict yourself to legitimate, trusted voices.

Re: Multiple Russia-aligned threat actors actively targeting Signal Messenger

#180

Post by inor0gu »

vetrom wrote: post #155
diputsmonro wrote: post #101

Earlier quoted context omitted.

If I'm reading that right, the attack assumes the attacker has (among other things) a private key (IK) stored only on the user's device, and the user's password. Thus, engaging on this attack would seem to require hardware access to one of the victims' devices (or some other backdoor), in which case you've already lost. Correct me if I'm wrong, but that doesn't seem particularly dangerous to me? As always, security o…

No, it means that if you approve a device to link, and you later have reason to unlink the device, you can't establish absolutely that the unlinked device can no longer access messages, or decrypt messages involving an account, breaking the forward-secrecy guarantees. That leaves you with the only remedy for a signal account that has accepted a link to a 'bad device' being to burn the whole account. (maybe rotating s…

That's not what the attack does tho - they have access to your private key so they can complete the linking protocol without your phone and add as many devices as they want (up to the allowed limit). If you add a bad device, you are screwed from that moment on, assuming you don't sync your chat history.

You can always see how many devices a user has: they have a unique integer id so if I wanna send you a message, I generate a new encrypted version for each device. If the UI does not show your devices properly than that is an oversight for sure, but I don't think it's the case anymore.

Either way, you'd have to trust that the Signal server is honest and tells you about all your devices. To avoid that, you need proofs that every Signal user has the save view on your account (keys), which is why key transparency is such an important feature.

Post reply on HN