4 ms·
/The likelihood that attackers have some database of victims + passwords seems low./ My impression is that most of these start with phishing, and probably even
by sdenton4 5y ago
/The likelihood that attackers have some database of victims + passwords seems low./
My impression is that most of these start with phishing, and probably even tailored phishing for larger organizations. A particular phishing campaign then just needs to include an encryption key, while the decryption key is kept elsewhere; this process is still quite easy to automate.
Hell, you could even just let loose lots of malware with different encryption keys, with the decrypting keys stored in a spreadsheet. When one succeeds, display a hash of the encryption key to the victim, and have them read it back to you when they call in to negotiate. And then just look up the paired decryption key when it's needed. No need to track anything, or bother with command+control.
- dredmorbius 5y agoAt some point there's a functional mapping from key to indicia. Releasing "lots of malware" either means a finite keyset, or a key-generation mechanism. At least as I see it. (I'd really like to find a detailed analysis of the malware software. There was an earlier version of the Darkside attack which used a weak mechansim for key generation.)
- adrian_b 5y agoThey would normally use a key-generation mechanism, but knowing that is not helpful at all. A typical key-generation mechanism would be for each malware copy to have a serial number and the keys to be generated by encrypting the serial number, e.g. with AES, using another secret key. Even if you know precisely the serial number of a copy and how the per-copy keys are generated by the attacker, you do not know the attacker's secret key used for key generation, so this is a dead end.
- dredmorbius 5y agoHow would the malware itself generate, or verify, the decryption key without the secret key? This is the distributed-secret-key problem.