The sender uses the key to encrypt the data while the receiver uses the same key to decrypt. In symmetric key encryption, the same key is used by both sender and receiver, which is also called the secret key. There are two types of cryptographic algorithms based on the kind of key used:Ī few assumptions before explaining the algorithm: the sender is the person who sends the data after encrypting it and the receiver is the person who decrypts the data with a key. Encryption algorithm, also called cipher.
To obfuscate its own code so that antivirus or security researchers cannot identify the actual code easily.Cryptography is a huge subject in itself and this section just gives a brief overview of cryptography. Malware can use cryptography for the following purposes: But before that, it’s important to take a look at the basics of cryptography.Ī lot of cryptographic algorithms are used by malware today. The ransomware uses a few cryptographic techniques to encrypt files, communicate with the C&C server, and so on. We will explain this in an example in the next section.
The ransom note instructs the victim on how to pay the ransom. It usually informs the victim that the files on his system have been encrypted and to decrypt them, he needs to pay a ransom. It is often termed a ransom note and is a message from the ransomware to the victim. After encrypting the files ransomware leaves a note for the victim.There is a huge list of crypto ransomware. Some crypto ransomwares also check to see whether the system is already infected by other crypto ransomware. They only need to execute on the system once to encrypt all files. Most crypto ransomwares don’t care about hiding in the system, so most do not have rootkit components either. The malware author need not write complex code, such as writing hooks to steal data. The malware just needs to browse through user directories to find relevant files that are likely to be personal and encrypt them. The reason for a possible increase in the use of crypto ransomware could be because coding it is quite easy compared to other malware. Only some make it into the limelight, while others fade away. In this article, you will get to know about Crypto Ransomware and how one can code it easily in order to encrypt certain directories and important files. There are a lot of variants in crypto ransomware. Crypto ransomware is the worst threat at present.