The WannaCry ransomware attack was a May 2017 worldwide cyberattack 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.
The attack began on Friday, 12 May 2017, and within a day was reported to have infected more than 230,000 computers in over 150 countries. Parts of the United Kingdom's National Health Service (NHS) were infected, causing it to run some services on an emergency-only basis during the attack, Spain's Telefónica, FedEx and Deutsche Bahn were hit, along with many other countries and companies worldwide. Shortly after the attack began, Marcus Hutchins, a 22-year-old web security researcher from North Devon in England then known as MalwareTech discovered an effective kill switch by registering a domain name he found in the code of the ransomware. This greatly slowed the spread of the infection, effectively halting the initial outbreak on Monday, 15 May 2017, but new versions have since been detected that lack the kill switch. Researchers have also found ways to recover data from infected machines under some circumstances.
WannaCry propagates using EternalBlue, an exploit of Windows' Server Message Block (SMB) protocol. Much of the attention and comment around the event was occasioned by the fact that the U.S. National Security Agency (NSA) 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, March 14, 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 7, Windows 8.1, Windows 10, Windows Server 2008, Windows Server 2012, and Windows Server 2016, in addition to Windows Vista (which had recently ended support). However, many Windows users had not installed the patches when, two months later on May 12, 2017, WannaCry used the EternalBlue vulnerability to spread itself. The next day, Microsoft released emergency security patches for Windows 7 and Windows 8. Organizations were advised to patch Windows and plug the vulnerability in order to protect themselves from the cyber attack.
Those still running older, unsupported versions of Microsoft Windows, such as Windows XP and Windows Server 2003, were initially at particular risk, but Microsoft released an emergency security patch for these platforms as well. Almost all victims of the cyberattack were running Windows 7, prompting a security researcher to argue that its effects on Windows XP users were "insignificant" in comparison.
Within four days of the initial outbreak, new infections had slowed to a trickle.
Several organizations released detailed technical writeups of the malware, including Microsoft, Cisco, Malwarebytes, Symantec and McAfee.
The "payload" works in the same fashion as most modern ransomware: it finds and encrypts a range of data files, then displays a "ransom note" informing the user and demanding a payment in bitcoin. 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.
Video WannaCry ransomware attack
Description
The WannaCry ransomware attack was a May 2017 worldwide cyberattack 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.
Maps WannaCry ransomware attack
"Kill switch"
The software contained a URL that, when discovered by a security researcher, Marcus Hutchins, and the corresponding domain registered to track activity from infected machines, was found to act as a "kill switch" that shut down the software before it executed its payload, stopping the spread of the ransomware. The researcher speculated that this had been included in the software as a mechanism to prevent it being run on quarantined machines used by anti-virus researchers; he observed that some sandbox environments will respond to all queries with traffic in order to trick the software into thinking that it is still connected to the internet, so the software attempts to contact an address which did not exist, to detect whether it was running in a sandbox, and do nothing if so. He also noted that it was not an unprecedented technique, having been observed in the Necurs trojan.
On 19 May, it was reported that hackers were trying to use a Mirai botnet variant to effect a distributed attack on WannaCry's kill-switch domain with the intention of knocking it offline. On 22 May, @MalwareTechBlog protected the domain by switching to a cached version of the site, capable of dealing with much higher traffic loads than the live site.
EternalBlue
The network infection vector, EternalBlue, was released by the hacker group called The Shadow Brokers on 14 April 2017, along with other tools apparently leaked from Equation Group, which is widely believed to be part of the United States National Security Agency.
EternalBlue exploits a vulnerability in Microsoft's implementation of the Server Message Block (SMB) protocol. This Windows vulnerability was not a zero-day flaw, but one for which Microsoft had released a "critical" advisory, along with a security patch to fix the vulnerability two months before, on 14 March 2017. The patch was to the Server Message Block (SMB) protocol used by Windows, and fixed several versions of the Microsoft Windows operating system, including Windows Vista, Windows 7, Windows 8.1, and Windows 10, as well as server and embedded versions such as Windows Server 2008 onwards and Windows Embedded POSReady 2009 respectively, but not the older unsupported Windows XP, Windows Server 2003, and Windows 8 (unsupported because Windows 8.1 is classified as a mandatory service pack upgrade). The day after the WannaCry outbreak Microsoft released updates for these too.
DoublePulsar
DoublePulsar is a backdoor tool, also released by The Shadow Brokers on 14 April 2017, Starting from 21 April 2017, security researchers reported that computers with the DoublePulsar backdoor installed were in the tens of thousands. By 25 April, reports estimated the number of infected computers to be up to several hundred thousands, with numbers increasing exponentially every day. The WannaCry code can take advantage of any existing DoublePulsar infection, or installs it itself.
Attribution
Linguistic analysis of the ransom notes indicated the authors were likely fluent in Chinese and proficient in English, as the versions of the notes in those languages were probably human-written while the rest seemed to be machine-translated.
Cybersecurity companies Kaspersky Lab and Symantec have both said the code has some similarities with that previously used by the Lazarus Group (believed to have carried out the cyberattack on Sony Pictures in 2014 and a Bangladesh bank heist in 2016--and linked to North Korea). This could also be either simple re-use of code by another group or an attempt to shift blame--as in a cyber false flag operation; but a leaked internal NSA memo is alleged to have also linked the creation of the worm to North Korea. The President of Microsoft said he believed North Korea was the originator of the WannaCry attack, and the UK's National Cyber Security Centre reached the same conclusion.
North Korea itself denies being responsible for the cyberattack.
Cyberattack
On 12 May 2017, WannaCry began affecting computers worldwide, with evidence pointing to an initial infection in Asia at 7:44am UTC. The initial infection was likely through an exposed vulnerable SMB port, rather than email phishing as initially assumed.
When executed, the 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 $300 in bitcoin within three days, or $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. As of 14 June 2017, at 00:18 ET, a total of 327 payments totaling $130,634.77 (51.62396539 XBT) had been transferred.
Organizations that had not installed Microsoft's security update were affected by the attack. Those still running the older Windows XP were at particularly high risk because no security patches had been released since April 2014 (with the exception of one emergency patch released in May 2014). However, on the day after the outbreak, an emergency, out-of-band security update was released for XP and Windows Server 2003. A Kaspersky Labs study reported that less than 0.1 percent of the affected computers were running Windows XP, and that 98 percent of the affected computers were running Windows 7. In a controlled testing environment, the cybersecurity firm Kryptos Logic found that they were unable to infect a Windows XP system with WannaCry using just the exploits, as the payload failed to load, or caused the operating system to crash rather than actually execute and encrypt files. However, when executed manually, WannaCry could still operate on Windows XP.
Ransomware analysis
The process of virus execution can be divided into three steps: the main program file uses the vulnerability to spread itself, and run "WannaCry" ransom program; "WannaCry" ransom program will encrypt the file; the ransom interface (@ WanaDecryptor @ .exe) displays the ransom information and decrypts the samples.
Main program (mssecsvc.exe) file analysis: The sample main program is the main spread program of this event that is responsible for spreading itself and releasing the "WannaCry" ransom program, and then "WannaCry" encrypts user files and execute malicious behavior.
"WannaCry" ransom program (tasksche.exe) analysis: The sample itself has an encrypted original RSA public key, and the attacker retains the decrypted RSA private key. Before encrypting the files, the CryptoAPI that calls Windows generates a new pair of RSA key, known as the sub-public key and sub-private key. And then, the sample encrypts the sub-private key with the original RSA public key and saves it as "00000000.eky" and the sub-public key is saved as "00000000.pky".
The sample generates an AES key for encrypting the file, the contents of the encrypted file are M2, and the AES key is encrypted with the sub-public key "00000000.pky". The contents of the encrypted file are M1. Then merge M1 and M2 and add file header "WANACRY!" to save the encrypted file.
When decrypting a file, the attacker decrypts the sub-private key "00000000.eky" and saves the file as "00000000.dky" for decrypting the file after receiving the decrypted file. The sample itself also has another pair of primary RSA public keys and private keys, which are used to decrypt the display files.
Each encrypted file uses a different AES key. If you want to decrypt the file, you need to acquire the RSA sub-private key, decrypt the AES key of the file header, and then use the AES key to decrypt files. If there is no RSA sub-private key, the AES key cannot be decrypted and the file cannot be decrypted.
Ransomware interface, decryption program (@WanaDecryptor@.exe) analysis: "@ WanaDecryptor @ .exe" is the ransomware interface program that displayed after sample has encrypted user data, which is responsible for displaying the Bitcoin wallet address and presenting part of the decrypted files. If wanting to decrypt all the files, you need to pay the "ransom". For darknet (Tor), the majority of infected users show the three default Bitcoin wallet address, which makes a lot of people think that the attacker cannot distinguish who paid the money and cannot decrypt the file for specified users.
Defensive response
Several hours after the initial release of the ransomware on 12 May 2017, while trying to establish the size of the attack, a researcher known by the name MalwareTech accidentally discovered what amounted to a "kill switch" hardcoded in the malware. Registering a domain name for a DNS sinkhole stopped the attack spreading as a worm, because the ransomware only encrypted the computer's files if it was unable to connect to that domain, which all computers infected with WannaCry before the website's registration had been unable to do. While this did not help already infected systems, it severely slowed the spread of the initial infection and gave time for defensive measures to be deployed worldwide, particularly in North America and Asia, which had not been attacked to the same extent as elsewhere.
On 16 May 2017, researchers from University College London and Boston University reported that their PayBreak system could defeat WannaCry and several other families of ransomware.
Within four days of the initial outbreak, new infections had slowed to a trickle.
It was discovered that Windows encryption APIs used by WannaCry may not completely clear the prime numbers used to generate the payload's private keys from the memory, making it possible to potentially retrieve the required key if they had not yet been overwritten or cleared from resident memory. This behaviour was used by a French researcher to develop a tool known as WannaKey, which automates this process on Windows XP systems. This approach was iterated upon by a second tool known as Wanakiwi, which was tested to work on Windows 7 and Server 2008 R2 as well.
The scale of the attack and subsequent exposure of vulnerabilities prompted Microsoft to release new security updates for older versions of Windows that are no longer supported, including for Windows XP, Windows Server 2003, Windows XP Embedded and Windows 7 Embedded. In a statement regarding the matter, the head of Microsoft's Cyber Defense Operations Center, Adrienne Hall, said that "Due to the elevated risk for destructive cyber-attacks at this time, we made the decision to take this action because applying these updates provides further protection against potential attacks with characteristics similar to WannaCrypt [alternative name to WannaCry]".
Advice on ransom
Experts advised against paying the ransom due to no reports of people getting their data back after payment and as high revenues would encourage more of such campaigns.
Impact
The ransomware campaign was unprecedented in scale according to Europol, which estimates that around 200,000 computers were infected across 150 countries. According to Kaspersky Lab, the four most affected countries were Russia, Ukraine, India and Taiwan.
The attack affected many National Health Service hospitals in England and Scotland, and up to 70,000 devices - including computers, MRI scanners, blood-storage refrigerators and theatre equipment - may have been affected. On 12 May, some NHS services had to turn away non-critical emergencies, and some ambulances were diverted. In 2016, thousands of computers in 42 separate NHS trusts in England were reported to be still running Windows XP. NHS hospitals in Wales and Northern Ireland were unaffected by the attack.
Nissan Motor Manufacturing UK in Tyne and Wear, England, halted production after the ransomware infected some of their systems. Renault also stopped production at several sites in an attempt to stop the spread of the ransomware.
The attack's impact is said to be relatively low compared to other potential attacks of the same type and could have been much worse had a security expert, who was independently researching the malware, not discovered that a kill-switch had been built in by its creators or if it had been specifically targeted on highly critical infrastructure, like nuclear power plants, dams or railway systems.
According to Cyber risk modeling firm Cyence, economic losses from the cyber attack could reach up to $4 billion, with other groups estimating the losses to be in the hundreds of millions.
EternalRocks
Via a honeypot mechanism, Security researcher Miroslav Stampar detected a new malware named "EternalRocks" that uses seven leaked NSA hacking tools and leaves Windows machines vulnerable for future attacks that may occur at any time. When installed, the worm names itself WannaCry in attempt to evade security experts.
Reactions
A number of experts highlighted the NSA's non-disclosure of the underlying vulnerability, and their loss of control over the EternalBlue attack tool that exploited it. Edward Snowden said that if the NSA had "privately disclosed the flaw used to attack hospitals when they found it, not when they lost it, the attack may not have happened". British cybersecurity expert Graham Cluley also sees "some culpability on the part of the U.S. intelligence services". According to him and others "they could have done something ages ago to get this problem fixed, and they didn't do it". He also said that despite obvious uses for such tools to spy on people of interest, they have a duty to protect their countries' citizens. Others have also commented that this attack shows that the practice of intelligence agencies to stockpile exploits for offensive purposes rather than disclosing them for defensive purposes may be problematic. Microsoft president and chief legal officer Brad Smith wrote, "Repeatedly, exploits in the hands of governments have leaked into the public domain and caused widespread damage. An equivalent scenario with conventional weapons would be the U.S. military having some of its Tomahawk missiles stolen." Russian President Vladimir Putin placed the responsibility of the attack on U.S. intelligence services, for having created EternalBlue.
On 17 May, United States bipartisan lawmakers introduced the PATCH Act that aims to have exploits reviewed by an independent board to "balance the need to disclose vulnerabilities with other national security interests while increasing transparency and accountability to maintain public trust in the process".
The United States Congress will also hold a hearing on the attack on June 15. Two subpanels of the House Science Committee will hear the testimonies from various individuals working in the government and non-governmental sector about how the US can improve its protection mechanisms for its systems against similar attacks in the future.
A cybersecurity researcher, working in loose collaboration with UK's National Cyber Security Centre, researched the malware and discovered a "kill switch". Later globally dispersed security researchers collaborated online to develop open source tools that allow for decryption without payment under some circumstances. Snowden states that when "[NSA]-enabled ransomware eats the Internet, help comes from researchers, not spy agencies" and asks why this is the case.
Other experts also used the publicity around the attack as a chance to reiterate the value and importance of having good, regular and secure backups, good cybersecurity including isolating critical systems, using appropriate software, and having the latest security patches installed. Adam Segal, director of the digital and cyberspace policy program at the Council on Foreign Relations, stated that "the patching and updating systems are broken, basically, in the private sector and in government agencies". In addition, Segal said that governments' apparent inability to secure vulnerabilities "opens a lot of questions about backdoors and access to encryption that the government argues it needs from the private sector for security". Arne Schönbohm, President of Germany's Federal Office for Information Security (BSI), stated that "the current attacks show how vulnerable our digital society is. It's a wake-up call for companies to finally take IT security [seriously]".
The effects of the attack also had political implications; in the United Kingdom, the impact on the National Health Service quickly became political, with claims that the effects were exacerbated by Government underfunding of the NHS; in particular, the NHS ceased its paid Custom Support arrangement to continue receiving support for unsupported Microsoft software used within the organization, including Windows XP. Home Secretary Amber Rudd refused to say whether patient data had been backed up, and Shadow Health Secretary Jon Ashworth accused Health Secretary Jeremy Hunt of refusing to act on a critical note from Microsoft, the National Cyber Security Centre (NCSC) and the National Crime Agency that had been received two months previously. Others argued that hardware and software vendors often fail to account for future security flaws, selling systems that - due to their technical design and market incentives - eventually won't be able to properly receive and apply patches. The NHS denied that it was still using XP, claiming only 4.7% of devices within the organization ran Windows XP.
Affected organizations
The following is an alphabetical list of organisations confirmed to have been affected:
See also
Notes
References
External links
- Ransom:Win32/WannaCrypt at Microsoft Malware Protection Center
- @actual_ransom on Twitter, a Twitterbot tracking the ransom payments
- Inside the digital heist that terrorized the world--and only made $100k
Source of the article : Wikipedia
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