This post was authored by Andrea Allievi and Earl Carter.
Ransomware holds a user’s data hostage. The latest ransomware variants encrypt the user’s data, thus making it unusable until a ransom is paid to retrieve the decryption key. The latest Cryptowall 2.0, utilizes TOR to obfuscate the command and control channel. The dropper utilizes multiple exploits to gain initial access and incorporates anti-vm and anti-emulation checks to hamper identification via sandboxes. The dropper and downloaded Cryptowall binary actually incorporate multiple levels of encryption. One of the most interesting aspects of this malware sample, however, is its capability to run 64 bit code directly from its 32 bit dropper. Under the Windows 32-bit on Windows 64-bit (WOW64) environment, it is indeed able to switch the processor execution context from 32 bit to 64 bit.
nd it needs to be quick, no matter the mix of applications on the network.
