Techbook

ImageSource TorrentLocker is a ‘Trojanhorse’ that encrypts files on the compromised computer using a symmetric block cipher AES to encrypt files and an asymmetric cipher RSA to encrypt the key. Monetary ransom is demanded by the criminals to unlock the infected computer. TorrentLocker was first observed in February 2014 and by the year end 5 major releases of this malware were discovered. TorrentLocker infections are initiated with a spam email. The victim is told to pay the amount in BitCoins that usually starts around $550 within 3 days.

  ImageSource TeslaCrypt now defunct was a ransomeware Trojan that first came into light in late February 2015. TeslaCrypt was distributed widely via the Angler exploit kit. It exploited AdobeFlash (CVE-2015-0311) and hence downloads the TeslaCrypt. Initially TeslaCrypt targeted game’s-play data for computer games like the  Call of Duty series, World of Warcraft, Mine-Craft & World of Tanks. Newer variants of TeslaCrypt were not only focused on games but also encrypted Word, PDF, JPEG and other files. In all cases, the victim would then be prompted to pay a ransom of $500 worth of BitCoins in order to obtain the key to decrypt the files.

KERANGER the first wild  MacOS Ransomware ! KeRanger also known by OSX.KeRanger.A is known as the first CryptoRansomware Trojan effectively targeting Apple computers. Discovered on March 4, 2016, has affected more than 7,000 Mac users. KeRanger is remotely executed on the victim's computer from a flaw in transmission of Bit Torrent client. The only way this malware could invade the victim's computer was by using a valid developer signature issued by Apple, that allowed it to bypass Apple's built-in OS X’s security feature designed to block software’s from untrusted sources. **The malware display’s a ransom message, demanding the victim to pay 1 BitCoin (~ $408)