The wanna cry ransomware attack was a worldwide attack by the WannaCry ransomware cryptoworm, which targeted computers running the Microsoft Windows operating system by encrypting data and demanding ransom payments in the Bitcoin cryptocurrency. It propagated through EternalBlue, an exploit developed by the United States National Security Agency (NSA) for older Windows systems. EternalBlue was stolen and leaked by a group called The Shadow Brokers a few months prior to the attack. While Microsoft had released patches previously to close the exploit, much of WannaCry's spread was from organizations that had not applied these, or were using older Windows systems that were past their end-of-life. WannaCry also took advantage of installing backdoors onto infected systems. The attack was stopped within a few days of its discovery due to emergency patches released by Microsoft, and the discovery of a kill switch that prevented infected computers from spreading WannaCry further. The attack was estimated to have affected more than 200,000 computers across 150 countries, with total damages ranging from hundreds of millions to billions of dollars. Security experts believed from preliminary evaluation of the worm that the attack originated from North Korea or agencies working for the country. In December 2017, the United States, United Kingdom and Australia formally asserted that North Korea was behind the attack. A new variant of WannaCry ransomware forced Taiwan Semiconductor Manufacturing Company (TSMC) to temporarily shut down several of its chip-fabrication factories in August 2018. The virus spread to 10,000 machines in TSMC's most advanced facilities.
WannaCry is a ransomware cryptoworm, which targeted computers running the Microsoft Windows operating system by encrypting data and demanding ransom payments in the Bitcoin cryptocurrency. The worm is also known as WannaCrypt, Wana Decrypt0r 2.0, WanaCrypt0r 2.0, and Wanna Decryptor. It is considered a network worm because it also includes a "transport" mechanism to automatically spread itself. This transport code scans for vulnerable systems, then uses the EternalBlue exploit to gain access, and the DoublePulsar tool to install and execute a copy of itself. WannaCry versions 0, 1, and 2 were created using Microsoft Visual C++ 6.0.
EternalBlue is an exploit of Windows' Server Message Block (SMB) protocol released by The Shadow Brokers. Much of the attention and comment around the event was occasioned by the fact that the U.S. National Security Agency (NSA) (from whom the exploit was likely stolen) had already discovered the vulnerability, but used it to create an exploit for its own offensive work, rather than report it to Microsoft. Microsoft eventually discovered the vulnerability, and on Tuesday, 14 March 2017, they issued security bulletin MS17-010, which detailed the flaw and announced that patches had been released for all Windows versions that were currently supported at that time, these being Windows Vista, Windows 7, Windows 8.1, Windows 10, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, and Windows Server 2016.
DoublePulsar is a backdoor tool, also released by The Shadow Brokers on 14 April 2017. Starting from 21 April 2017, security researchers reported that there were tens of thousands of computers with the DoublePulsar backdoor installed. By 25 April, reports estimated that the number of infected computers could be up to several hundred thousand, with numbers increasing every day. The WannaCry code can take advantage of any existing DoublePulsar infection, or installs it itself.
When executed, the WannaCry malware first checks the "kill switch" domain name; if it is not found, then the ransomware encrypts the computer's data, then attempts to exploit the SMB vulnerability to spread out to random computers on the Internet, and "laterally" to computers on the same network. As with other modern ransomware, the payload displays a message informing the user that files have been encrypted, and demands a payment of around US$300 in bitcoin within three days, or US$600 within seven days. Three hardcoded bitcoin addresses, or "wallets", are used to receive the payments of victims. As with all such wallets, their transactions and balances are publicly accessible even though the cryptocurrency wallet owners remain unknown.