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Lenovo finally seem to understand that they hosed up, but Superfish thinks everything is fine with their software except for those meanie bloggers spreading lies.
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Feb 21, 2015 03:29
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Next week at the malaria user group meeting..,
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Feb 21, 2015 15:00
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The Superfish stuff is comically, implausibly broken. I don't think any of us realized how deep the pit of stupidity would go while it was playing out. At this point we're lucky that it doesn't execute base64'd x86 machine code stored in some extended attribute.
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Feb 22, 2015 05:13
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Khablam posted:The private key (the one you need to decrypt) never leaves their server. Whoa, it really does asymmetric encryption over gigabytes of data? I'd have thought that to be prohibitively slow, even if they used something faster than RSA. Do you know what cryptosystem is typically used?
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Jun 22, 2015 13:57
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ElZilcho posted:RSA is simply the key exchange/generation mechanism, AES256 seems to be the cipher of choice. But AES is symmetric, so the decryption-capable key then has to reside in process memory during the locking process, rather than only on the attacker's server. I don't understand how or why you would use RSA to generate a key for AES, though I'm not really even an amateur cryptographer. By exchange I assume you mean the usual encrypt-symmetric-key-with-asymmetric-cipher sort of bootstrapping protocol?
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Jun 22, 2015 18:42
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I expected that it would generate a symmetric key, encrypt that symkey with the attacker's pubkey, encrypt the data with the symkey, and pop the alert. To unlock it sends the encrypted key to the C2 server which then gives back the symkey if payment has been rendered. But the assertion was that the decryption key was never outside the attacker's server, which I think means there can't be a symmetric key involved. Otherwise dumping the process memory would let you recover the key without paying the ransom. Being slow is probably OK, though.
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Jun 22, 2015 21:55
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Khablam posted:If it's AES over RSA then it probably works like SSL encryption, where it's the actual symmetrical key itself that is exchanged/protected via RSA and the actual file-level encoding is done via AES. Either way, no part of your computer, drive, RAM or CPU actually sees (or needs to see) the private key to encrypt the data. This is categorically false. If the cipher used to encrypt the file is symmetric, like AES, then the decryption key is identical to the encryption key, and the computer simply must have access to the encryption key in order to encrypt. That characteristic of symmetric ciphers is what motivated the developing of public-key cryptography, really. PGP uses an asymmetric cipher to protect a symmetric key similarly to an SSL key exchange, because asymmetric crypto is (was?) too expensive to use on arbitrarily-large cleartext. That expense is what led to my initial question, since afaik it's the only alternative to the decryption key being resident on the victim computer.
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Jun 22, 2015 23:42
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So, uh, does anyone actually know the crypto mechanics of these things?
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Jun 23, 2015 14:08
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Thanks, that's exactly what I was interested in. Does it rotate AES keys by any chance, so that some encrypted files are still locked even if it's caught and a key is extracted from memory?
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Jun 23, 2015 15:42
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pixaal posted:Let's in theory say you could, this would require that you know its running to reverse it. It would be a simple party trick and nothing more. You wouldn't know its running until its too late, that is the point of it. I don't think it's uncommon for it to be detected in progress due to file server overload or similar, but I don't have personal experience with it.
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Jun 23, 2015 15:54
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In fact, this subthread started with someone saying they'd dumped the process in question, I think.
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Jun 23, 2015 16:22
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Khablam posted:But when someone prefaces their question with "I don't know much about crypto" Who said that? I have a pretty decent grounding in crypto, I was asking about the details of the mechanism and key management. Both PGP and HTTPS lack the property of keeping the decryption key off of the encrypting computer, which was the assertion to which I was responding in the first place.
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Jun 23, 2015 22:29
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Yeah, it was a hysterical concession, but not even Taher minded.
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Aug 28, 2015 06:25
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dpbjinc posted:TLS isn't even an accurate name. It secures the Application layer, not the Transport layer. How so?
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Aug 28, 2015 20:31
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Do you also incinerate laptops if they get owned, or do you just reinstall the software stack? If you don't reuse compromised hardware after restoring from a known source, can I have your old stuff? I promise to be very careful with it.
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Oct 5, 2015 21:02
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Can I have your stuff? I was thinking of reflashing like one does after bricking a device, but if you don't have a trusted channel for the reflashing then I can see the concern. Of course, I don't think I would reflash my PC BIOS (and video card, and so forth) as part of eradicating malware either, so maybe I'm just insufficiently paranoid.
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Oct 5, 2015 21:24
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Prosthetic_Mind posted:Can your PC BIOS potentially subvert all communication going between your network and the internet to do things like steal banking and other information, as well as act as part of a botnet? My PC BIOS can potentially subvert anything, it controls the way the OS gets loaded. It was in the NSA's catalog of dirty tricks that got leaked a couple years back, and Equation Group was doing it with drive firmware too. E: http://www.wired.com/2015/02/nsa-firmware-hacking/ has a good overview. I don't even know how to reflash my drive firmware in a trusted way, so I guess I really should be pulverizing equipment and hitting NewEgg from a trusted device if I get owned... Subjunctive fucked around with this message at 22:14 on Oct 5, 2015 |
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Oct 5, 2015 22:11
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wyoak posted:It's certainly a matter of risk assessment vs cost but new routers are like $80 so pony up lol at your peasant router I bet it doesn't even have an app But yes, I was responding to the "potentially" aspect. I think I would be OK with tftp reflashing versus landfill for this case myself.
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Oct 5, 2015 22:41
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The cheaper ones they can probably compromise during manufacturing.
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Oct 6, 2015 04:55
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oh bean dip you have a full-take feed from my heart
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Oct 6, 2015 05:12
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In my business environment, if I get malware on my machine, I get a new piece of hardware and my documents copied over (but nothing executable and no source trees) while they analyze the victim machine. "In a business environment" doesn't excuse putting the business at unnecessary risk, and it's irresponsible to let customers think you've remediated the situation by buffing out the scratches just because they don't want to wait for the body work. (That's part of why I stopped doing security consulting many years ago. Clients wanted guarantees I couldn't give them, or me to give them approval for expedience that didn't match their stated threat stance. If someone at the customer wants to say it's all better because they deleted the php script payload from the web root, they can do that, but I'm not going to.)
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Oct 23, 2015 04:20
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mindphlux posted:no, I actually have asked about 5 times for examples of how you guys propose to handle malware/virus problems in a reasonable amount of time. I outlined my SOP line by line, please outline yours line by line. You say it's not practical, but treating it as a hardware failure and taking it out of circulation until it's restored from zero is something that actual large companies do. Give them a loaner like you would if their drive died, and restore them from backup. Your position seems to be that while it's the right thing, it takes too long. Maybe that's the case for your MSP business, and that the service you provide is "as much as we can do in an hour" rather than "clean according to best practices". That could even be what your customers prefer, hopefully on an informed basis. Even then, why would you recommend that to an individual who hasn't indicated that they're similarly time-constrained? Why not recommend the right thing to start with?
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Oct 27, 2015 15:19
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mindphlux posted:w/rt clients : some have spare machines, some have budgets where the concept of 'a spare machine' is laughed at. 'we'll buy it when we need it!!' or 'why are you asking me to spend $1000 and hours of billable time on something that I'm not going to use'. I'm good at persuading and justifying a responsible approach to IT, but unless you've worked for a MSP, I don't think you'd understand what you're up against. What do you tell customers when you return their computer to them? That you cleaned it up a bit; that you've verified it's clean; that it's safe to use? I've been a consultant, I understand that customers don't always want to buy the thing you genuinely think is best for them. I'm curious about how you frame what they *do* ask for and get.
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Oct 27, 2015 19:15
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Thanks, I understand better now. Appreciate it.
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Oct 28, 2015 11:02
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Wiggly Wayne DDS posted:It really does though, here's a breakdown of x86 security: That's not a fun paper to read.
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Oct 28, 2015 20:35
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Ynglaur posted:Oh cool! She had stopped blogging for awhile, so I thought she had fallen off the face of the earth or angered Put in or something. None of us want this thread, but you especially don't want this thread.
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Oct 29, 2015 04:32
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Khablam posted:Your ranting and cries of fraud and negligence over the posted SOP are an insane reaction but maybe I'm just expecting too much from a yospos poster. Don't be racist.
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Oct 29, 2015 13:52
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| # ¿ May 17, 2024 17:40 |
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Mido posted:OSI is posting not to attack you Well...
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Oct 30, 2015 00:38
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