78

I don't think you will see those files again, unless you have a back up. You can view the transaction history of the Bitcoin address you were asked to pay to here. As you can see, there are 303 transactions in total and many of them are for 1 BTC. That implies that the same Bitcoin address have been given to multiple victims. This in turn means that it is ...


63

Yes. It's called a Man-in-the-Middle attack. You terminate the SSL session at a mid-point, thereby having the encryption key, then create a new session to the target server, so you have that encryption key too. The data path now goes User->MitM->Server, where each of the arrows is an encrypted connection. Data returned from the server goes Server->MitM->User,...


57

Considering those compromises you mention, do you think that encrypting files yourself will be easy? How do you know you won't get into those same pitfalls that resulted in compromises of password managers? AES 256 is believed to be computationally secure. Every computer ever made working simultaneously to brute force the key, working since the beginning of ...


53

The = signs relate to the length of the string being encoded in Base64. Essentially, in probably the most common form of Base64, = is used as a padding character to ensure that the last block can be decoded properly. Base64 is not encryption - there is no hiding going on in it - but is often used to allow for binary data to be sent in text only form. All ...


51

The Zodiac killer ciphers are an interesting case. As there were four ciphers sent to the local papers, I will address each in turn. They do share some common traits however. They are each their own cipher, so the 'solution' used for cipher 408 cannot be applied to the other messages. Each message has a unique character count. The Zodiac Killer sent these ...


43

The whole point of having a passphrase is to lock out anyone who does not know it. Allowing it to be recovered would defy the principle and allow hackers who get access to your certificate to recover your keys. So no, there is no such thing. What you should do is declare the keys as lost to the issuer so that they revoke your certificate. Then, you have to ...


34

"Encryption" is a large term. In all generality, encryption takes an input message in some space of possible input messages; usually arbitrary "sequences of bits" with various restrictions on length, e.g. "length in bits must be a multiple of 8" (i.e. input must be a sequence of bytes), or "length must not exceed 245 bytes" (typical of asymmetric encryption ...


34

No, there's no way such a thing could possibly exist, for any significant amount of time. There's two big hints at this in the article itself: many technical experts are raising equally serious doubts about its feasibility A Home Office spokesman said – “We have not issued any hardware or software specifications. The only way this could work on a ...


27

You're assuming that they're actually encrypted. A lot of crazy people have written things that nobody understands. Just because the author thinks they're in code doesn't necessarily mean that the code can be reversed.


21

First line of defense: BACKUPS. Restore the files from there. When available, this has a 100% chance of success. Otherwise: hope that the ransomware did not disable/work around the Windows Shadow Copy service and that it was active to begin with. Choose one of the files, right click, Properties, "Previous Versions". Is there a previous version from before ...


17

Yes, some have apparently gotten their files decrypted after paying the ransom. We have confirmation that some of the 200+ #WannaCry victims who have paid the ransom have gotten their files back. Still, not recommended. (tweeted by Mikko Hypponen, CRO at F-Secure, on May 15, 2017) But there is absolutely no guarantee to get yours decrypted after paying ...


16

Europol has a web page with a contact form that you can use to check if a solution is available to your friend's problem. https://www.nomoreransom.org/


14

First: there's no known way to decrypt files attacked by CryptoWall. Unless you pay to get the key, they are lost forever. If you don't have offline backups, your files are lost. One way to prevent the execution of those kind of viruses is to use whitelisting on your Windows. This can be frustrating if your father does not know how to include applications ...


14

I think you've gotten public key cryptography all out of whack, here. You don't give out a private key. Period. They're called "private" for a reason. You don't send an encrypted message along the same channel, let alone at the same time, as you send the only key that is needed to decrypt it. That completely defeats the purpose of the encryption in the ...


14

From your description, it sounds like the server is currently using the key, which means the server "knows" the pass phrase. If this is correct and you have appropriate access to the server, you should be able to extract it. How you'd do that depends on what the server software is and how it's set up. Just as an example, if you were running Apache, and it ...


13

It's safe as long as you understand the implications. Fiddler acts as a proxy / man in the middle to intercept and decrypt traffic between you and the target. For SSL sites, it does this by dynamically generating an SSL certificate with the name of the target. The problem is that your browser will not trust certificates issued by Fiddler, hence the ...


12

The black box is theoretically possible, but is practically impossible. In order for it to work the CAs would have to cooperate and be willing to provide the Black Box with legitimate certificates for every website that provides email services. Otherwise end users would receive certificate warnings in their browsers which would warn them that a MITM attack ...


12

You'd lose the ability to generate random passwords at the click of a button, which might mean you tend towards weaker passwords from the lack of convenience - one of the benefits of password manager apps, whether online or offline, is the generation of long random strings. However, you would keep the security of the passwords being safe if you lost a copy ...


11

Is there a way to decrypt the files? SensorsTechForum suggests to try Kaspersky’s RectorDecryptor.exe and RakhniDecryptor.exe. However, I would not hold out much hope. As CryptoWall is very similar to CryptoDefense, you may be able to decrypt using the method here. Unfortunately, this only really applies if you were infected before April 1st 2014. You ...


11

When trying to access the content of a hard-drive, you have to use the interface provided by said hard-drive. It usually comes with a firmware. Currently, it is stated that this firmware will not allow data to be read without providing the correct password and that in case of 10 failed attempts, the data would be deleted. To circumvent the restriction, ...


11

Under some circumstances it may be possible to recover the private key with a new password. It would require the issuing CA to have created the certificate with support for private key recovery. This is normally not done, except where the key is used to encrypt information, e.g. when used for email or file encryption. The issuing CA should be able to tell ...


10

AES decryption with the key can definitly happen at GB/s on modern Intel CPUs. Brute-forcing the entire AES keyspace (e.g. 2^128 possibilities) is considered impossible today by a very large margin (more time than the age of the universe). AES is regarded as so strong that known-plaintext attacks and differential cryptanalysis can be compared to brute ...


10

How are passwords stored? Passwords are not (or at least should not be) stored using encryption. They should be stored using a hashing algorithm. So if you are trying to decrypt it to recover the original password, then that isn't going to work. Here are some links to read about how password storage works: https://crackstation.net/hashing-security.htm#...


9

The way that I understand that Fiddler (And similar proxyies such as Burp or OWASP ZAP) work is that each installation generates a unique root certificate which it then uses to generate certificates on the fly when you have it assigned as a proxy, so you can intercept and modify traffic flowing over this connection (the purpose of the software). As the root ...


8

There is no need to know the key of the relays to decrypt the data they send back. TOR works the in the same way as SSL/TLS does: when you connect via HTTPS (HTTP over SSL/TLS) to a web server, you don't need to know the key of the server to decrypt the data you receive from it, this because during the SSL handshake phase, your browser and the server agreed ...


8

A peek at the source code, especially the AES256BitExpress.cs file, reveals the following excerpt: public static byte[] AES_Encrypt(byte[] bytesToBeEncrypted, byte[] passwordBytes) { byte[] encryptedBytes = null; byte[] saltBytes = passwordBytes; using (MemoryStream ms = new MemoryStream()) { using (...


8

To encrypt a file for a recipient: $ gpg -ea -r foo@example.com < file > file.gpg To get the session key for an encrypted file when you have the private key of the recipient: $ gpg --show-session-key < file.gpg ... gpg: session key: `9:901D6ED579AFF935F9F157A5198BCE48B50AD87345DEADBA06F42C5D018C78CC' ... To use this session key to decrypt the ...


8

As far as our current knowledge goes, there is only brute force available. Ask the person who created the key to try to remember the passphrase and try. If this is not available, try a cracking program that generates popular passwords as a passphrase generator. However, when the passphrase was well chosen, your chances to crack the key are minimal.


8

First, there is a difference between hashing and encryption. SHA256 is a hashing function, not an encryption function. Secondly, since SHA256 is not an encryption function, it cannot be decrypted. What you mean is probably reversing it. In that case, SHA256 cannot be reversed because it's a one-way function. Reversing it would cause a preimage attack, which ...


8

You are asking us for the best way to shoot yourself in the foot. As Peter Harmann says, there is absolutely no legitimate reason to do password recovery by decrypting and emailing passwords. If you can decrypt the passwords, an attacker could potentially do the same. The whole point of password hashing is to avoid that! Additionally, email is not a very ...


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