TrojanCrypt.VB.U offers victims a ‘trial’ version of the software to prove its ability to unlock files. The malware’s real innovation is its attempt to overcome reluctant victims’ willingness to pay the fee by offering to decrypt three files in advance of them buying a full license. The type of encryption used turns out to be a simple type of XOR algorithm, which means that decryption would not require huge brute force to break in this instance. The Trojan Trojan is the latest in a long line of malware that has been used to extort money from users.”]
Source: https://www.csoonline.com/article/2130499/new-ransom-trojan-cons-victims-with–trial–version.html