Ransomware is a type ofmalware thatencrypts the victim'spersonal data until aransom is paid.[1][2][3][4][5] Difficult-to-tracedigital currencies such aspaysafecard orBitcoin and othercryptocurrencies are commonly used for the ransoms, making tracing and prosecuting the perpetrators difficult. Sometimes the original files can be retrieved without paying the ransom due to implementation mistakes, leaked cryptographic keys or a complete lack of encryption in the ransomware.
Ransomware attacks are typically carried out using aTrojan disguised as a legitimate file that the user is tricked into downloading or opening when it arrives as an email attachment. However, one high-profile example, theWannaCry worm, traveled automatically between computers without user interaction.[6]
Starting as early as 1989 with the first documented ransomware known as theAIDS trojan, the use of ransomware scams grew internationally.[7][8][9] There were 181.5 million ransomware attacks worldwide in the first six months of 2018, 229% more than the first six months of 2017.[10] In June 2014,security software companyMcAfee released data showing that it had collected more than double the number of ransomware samples that quarter than it had in the same quarter the previous year.[11]CryptoLocker was particularly successful, procuring an estimated US$3 million before it was taken down by authorities,[12] and CryptoWall was estimated by the USFederal Bureau of Investigation (FBI) to have accrued over US$18 million by June 2015.[13] In 2020, the USInternet Crime Complaint Center (IC3) received 2,474 complaints identified as ransomware, with adjusted losses of over $29.1 million. The losses could exceed this amount, according to the FBI.[14] Globally, according toStatistica, there were about 623 million ransomware attacks in 2021, and 493 million in 2022.[15]
Ransomware payments were estimated at $1.1bn in 2019,[16] $999m in 2020, a record $1.25bn in 2023, and a sharp drop to $813m in 2024,[17] attributed to non-payment by victims and action by law enforcement.
The concept of file-encrypting ransomware was invented and implemented by Young andYung atColumbia University and was presented at the 1996 IEEE Security & Privacy conference. It is calledcryptoviral extortion and it was inspired by the fictional facehugger in the movieAlien.[18] Cryptoviral extortion is the following three-round protocol carried out between the attacker and the victim.[1]
[attacker→victim] The attacker generates a key pair and places the corresponding public key in the malware. The malware is released.
[victim→attacker] To carry out the cryptoviral extortion attack, the malware generates a randomsymmetric key and encrypts the victim's data with it. It uses the public key in the malware to encrypt the symmetric key. This is known ashybrid encryption and it results in a small asymmetric ciphertext as well as the symmetric ciphertext of the victim's data. Itzeroizes the symmetric key and the original plaintext data to prevent recovery. It puts up a message to the user that includes the asymmetric ciphertext and how to pay the ransom. The victim sends the asymmetric ciphertext and e-money to the attacker.
[attacker→victim] The attacker receives the payment, deciphers the asymmetric ciphertext with the attacker's private key, and sends the symmetric key to the victim. The victim deciphers the encrypted data with the needed symmetric key thereby completing the cryptovirology attack.
Thesymmetric key is randomly generated and will not assist other victims. At no point is the attacker's private key exposed to victims and the victim need only send a very small ciphertext (the encrypted symmetric-cipher key) to the attacker.
Ransomware attacks are typically carried out using aTrojan, entering a system through, for example, a malicious attachment, an embedded link in aphishing email, or a vulnerability in a network service. The program then runs apayload, which locks the system in some fashion, or claims to lock the system but does not (e.g., ascareware program). Payloads may display a fake warning purportedly by an entity such as alaw enforcement agency, falsely claiming that the system has been used for illegal activities, contains content such aspornography and"pirated" media.[19][20][21]
Some payloads consist simply of an application designed to lock or restrict the system until payment is made, typically by setting theWindows Shell to itself,[22] or even modifying themaster boot record and/orpartition table to prevent the operating system from booting until it is repaired.[23] The most sophisticated payloadsencrypt files, with many usingstrong encryption toencrypt the victim's files in such a way that only the malware author has the needed decryption key.[1][24][25]
Payment is virtually always the goal, and the victim iscoerced into paying for the ransomware to be removed either by supplying a program that can decrypt the files, or by sending an unlock code that undoes the payload's changes. While the attacker may simply take the money without returning the victim's files, it is in the attacker's best interest to perform the decryption as agreed, since victims will stop sending payments if it becomes known that they serve no purpose. A key element in making ransomware work for the attacker is a convenient payment system that is hard to trace. A range of such payment methods have been used, includingwire transfers,premium-rate text messages,[26] pre-paidvoucher services such aspaysafecard,[7][27][28] and theBitcoincryptocurrency.[29][30][31]
In May 2020, vendor Sophos reported that the global average cost to remediate a ransomware attack (considering downtime, people time, device cost, network cost, lost opportunity and ransom paid) was $761,106. Ninety-five percent of organizations that paid the ransom had their data restored.[32]
The first known malware extortion attack, the"AIDS Trojan" written by Joseph Popp in 1989, had a design failure so severe it was not necessary to pay the extortionist at all. Its payload hid the files on the hard drive and encrypted only theirnames, and displayed a message claiming that the user's license to use a certain piece of software had expired. The user was asked to payUS$189 to "PC Cyborg Corporation" in order to obtain a repair tool even though the decryption key could be extracted from the code of the Trojan. The Trojan was also known as "PC Cyborg". Popp was declaredmentally unfit to stand trial for his actions, but he promised to donate the profits from the malware to fundAIDS research.[33]
The idea of abusing anonymous cash systems to safely collect ransom from humankidnapping was introduced in 1992 by Sebastiaan von Solms andDavid Naccache.[34] This electronic money collection method was also proposed for cryptoviral extortion attacks.[1] In the von Solms-Naccache scenario a newspaper publication was used (since bitcoin ledgers did not exist at the time the paper was written).
The notion of using public key cryptography for data kidnapping attacks was introduced in 1996 by Adam L. Young andMoti Yung. Young and Yung critiqued the failed AIDS Information Trojan that relied onsymmetric cryptography alone, the fatal flaw being that the decryption key could be extracted from the Trojan, and implemented an experimental proof-of-concept cryptovirus on aMacintosh SE/30 that usedRSA and theTiny Encryption Algorithm (TEA) tohybrid encrypt the victim's data. Sincepublic key cryptography is used, the virus only contains theencryption key. The attacker keeps the correspondingprivate decryption key private. Young and Yung's original experimental cryptovirus had the victim send the asymmetric ciphertext to the attacker who deciphers it and returns the symmetric decryption key it contains to the victim for a fee. Long beforeelectronic money existed Young and Yung proposed that electronic money could be extorted through encryption as well, stating that "the virus writer can effectively hold all of the money ransom until half of it is given to him. Even if the e-money was previously encrypted by the user, it is of no use to the user if it gets encrypted by a cryptovirus".[1] They referred to these attacks as being "cryptoviral extortion", an overt attack that is part of a larger class of attacks in a field calledcryptovirology, which encompasses both overt and covert attacks.[1] The cryptoviral extortion protocol was inspired by the parasitic relationship between H. R. Giger's facehugger and its host in the movieAlien.[1][18]
Examples of extortionate ransomware became prominent in May 2005.[35] By mid-2006, Trojans such asGpcode, TROJ.RANSOM.A,Archiveus, Krotten, Cryzip, and MayArchive began utilizing more sophisticated RSA encryption schemes, with ever-increasing key-sizes. Gpcode.AG, which was detected in June 2006, was encrypted with a 660-bit RSA public key.[36] In June 2008, a variant known as Gpcode.AK was detected. Using a 1024-bit RSA key, it was believed large enough to be computationally infeasible to break without a concerteddistributed effort.[37][38][39][40]
Encrypting ransomware returned to prominence in late 2013 with the propagation ofCryptoLocker—using theBitcoindigital currency platform to collect ransom money. In December 2013,ZDNet estimated based on Bitcoin transaction information that between 15 October and 18 December, the operators of CryptoLocker had procured about US$27 million from infected users.[41] The CryptoLocker technique waswidely copied in the months following, including CryptoLocker 2.0 (thought not to be related to CryptoLocker), CryptoDefense (which initially contained a major design flaw that stored the private key on the infected system in auser-retrievable location, due to its use of Windows' built-in encryption APIs),[30][42][43][44] and the August 2014 discovery of a Trojan specifically targetingnetwork-attached storage devices produced bySynology.[45] In January 2015, it was reported that ransomware-styled attacks have occurred against individual websites via hacking, and through ransomware designed to targetLinux-basedweb servers.[46][47][48]
In 2022, Costa Rica received widespreadConti ransomware attacks affecting government, healthcare and industry.[49] This led President Rodrigo Chaves to declare a state of emergency and announce that Costa Rica is "at war" with its ransomware hackers.[50]
In some infections, there is a two-stage payload, common in many malware systems. The user is tricked into running a script, which downloads the main virus and executes it. In early versions of the dual-payload system, the script was contained in a Microsoft Office document with an attached VBScript macro, or in a windows scripting facility (WSF) file. As detection systems started blocking these first stage payloads, the Microsoft Malware Protection Center identified a trend away towardLNK files with self-contained Microsoft WindowsPowerShell scripts.[51] In 2016, PowerShell was found to be involved in nearly 40% of endpoint security incidents.[52]
Some ransomware strains have usedproxies tied toTorhidden services to connect to theircommand and control servers, increasing the difficulty of tracing the exact location of the criminals.[53][54] Furthermore,dark web vendors have increasingly[when?] started to offer the technologyas a service, wherein ransomware is sold, ready for deployment on victims' machines, on a subscription basis, similarly to Adobe Creative Cloud or Office 365.[54][55][56]
Symantec has classified ransomware to be the most dangerous cyber threat.[57]
In August 2010, Russian authorities arrested nine individuals connected to a ransomware Trojan known as WinLock. Unlike the previous Gpcode Trojan, WinLock did not use encryption. Instead, WinLock trivially restricted access to the system by displaying pornographic images and asked users to send apremium-rate SMS (costing around US$10) to receive a code that could be used to unlock their machines. The scam hit numerous users across Russia and neighbouring countries—reportedly earning the group over US$16 million.[21][58]
In 2011, a ransomware Trojan surfaced that imitated theWindows Product Activation notice, and informed users that a system's Windows installation had to be re-activated due to "[being a] victim of fraud". An online activation option was offered (like the actual Windows activation process), but was unavailable, requiring the user to call one of sixinternational numbers to input a 6-digit code. While the malware claimed that this call would be free, it was routed through a rogue operator in a country with high international phone rates, who placed the call on hold, causing the user to incur large internationallong-distance charges.[19]
In 2012, Symantec reported spread out of Eastern Europe of ransomware with a lock screen purporting to be law enforcement demanding payment for illegal activity.[59]
In February 2013, a ransomware Trojan based on the Stamp.EKexploit kit surfaced; the malware was distributed via sites hosted on the project hosting servicesSourceForge andGitHub that claimed to offer "fake nude pics" of celebrities.[60] In July 2013, anOS X-specific ransomware Trojan surfaced, which displays a web page that accuses the user of downloading pornography. Unlike its Windows-based counterparts, it does not block the entire computer, but simplyexploits the behaviour of the web browser itself to frustrate attempts to close the page through normal means.[61]
In July 2013, a 21-year-old man from Virginia, whose computer coincidentally did contain pornographic photographs of underage girls with whom he had conducted sexualized communications, turned himself in to police after receiving and being deceived byFBI MoneyPak Ransomware accusing him of possessing child pornography. An investigation discovered the incriminating files, and the man was charged withchild sexual abuse and possession of child pornography.[62]
The converse of ransomware is acryptovirology attack invented by Adam L. Young that threatens to publish stolen information from the victim's computer system rather than deny the victim access to it.[63] In a leakware attack, malware exfiltrates sensitive host data either to the attacker or alternatively, to remote instances of the malware, and the attacker threatens to publish the victim's data unless a ransom is paid. The attack was presented atWest Point in 2003 and was summarized in the bookMalicious Cryptography as follows, "The attack differs from the extortion attack in the following way. In the extortion attack, the victim is denied access to its own valuable information and has to pay to get it back, where in the attack that is presented here the victim retains access to the information but its disclosure is at the discretion of the computer virus".[64] The attack is rooted in game theory and was originally dubbed "non-zero sum games and survivable malware". The attack can yield monetary gain in cases where the malware acquires access to information that may damage the victim user or organization, e.g., the reputational damage that could result from publishing proof that the attack itself was a success.
Common targets for exfiltration include:
third party information stored by the primary victim (such as customer account information or health records);
information proprietary to the victim (such as trade secrets and product information)
embarrassing information (such as the victim's health information or information about the victim's personal past)
Exfiltration attacks are usually targeted, with a curated victim list, and often preliminary surveillance of the victim's systems to find potential data targets and weaknesses.[65][66]
With the increased popularity of ransomware on PC platforms, ransomware targetingmobile operating systems has also proliferated. Typically, mobile ransomware payloads are blockers, as there is little incentive to encrypt data since it can be easily restored via online synchronization.[67] Mobile ransomware typically targets theAndroid platform, as it allows applications to be installed from third-party sources.[67][68] The payload is typically distributed as anAPK file installed by an unsuspecting user; it may attempt to display a blocking message over top of all other applications,[68] while another used a form ofclickjacking to cause the user to give it "device administrator" privileges to achieve deeper access to the system.[69]
Different tactics have been used oniOS devices, such as exploitingiCloud accounts and using theFind My iPhone system to lock access to the device.[70] OniOS 10.3, Apple patched a bug in the handling of JavaScript pop-up windows inSafari that had been exploited by ransomware websites.[71]It recently[when?] has been shown that ransomware may also target ARM architectures like those that can be found in various Internet-of-Things (IoT) devices, such as Industrial IoT edge devices.[72]
In August 2019 researchers demonstrated it is possible to infectDSLR cameras with ransomware.[73] Digital cameras often usePicture Transfer Protocol (PTP - standard protocol used to transfer files.) Researchers found that it was possible to exploit vulnerabilities in the protocol to infect target camera(s) with ransomware (or execute any arbitrary code). This attack was presented at theDefcon security conference in Las Vegas as a proof of concept attack (not as actual armed malware).
The first attacks were on random users, typically infected through email attachments sent by small groups of criminals, demanding a few hundred dollars in cryptocurrency to unlock files (typically a private individual's photographs and documents) that the ransomware had encrypted. As ransomware matured as a business, organised gangs entered the field, advertising on thedark Web for experts, andoutsourcing functions. This led to improvement in the quality of ransomware and its success. Rather than random emails, the gangs stole credentials, found vulnerabilities in target networks, and improved the malware to avoid detection by anti-malware scanners. Ransoms demanded escalated into the much larger sums (millions) that an enterprise would pay to recover its data, rather than what an individual would pay for their documents (hundreds).
In 2016, a significant uptick in ransomware attacks on hospitals was noted. According to the 2017 Internet Security Threat Report from Symantec Corp, ransomware affected not only IT systems but also patient care, clinical operations, and billing. Online criminals may be motivated by the money available and sense of urgency within the healthcare system.[74]
Ransomware is growing rapidly across the internet users but also for the IoT environment.[59] The big problem is that millions of dollars are lost by some organizations and industries that have decided to pay, such as the Hollywood Presbyterian Medical Center and the MedStar Health.[75]
According to Symantec 2019 ISTR report, for the first time since 2013, in 2018 there was an observed decrease in ransomware activity with a drop of 20 percent. Before 2017, consumers were the preferred victims, but in 2017 this changed dramatically, it moved to the enterprises. In 2018 this path accelerated with 81 percent infections which represented a 12 percent increase.[76] The common distribution method today is based on email campaigns.
In late 2019 ransomware group Maze downloaded companies' sensitive files before locking them, and threatened to leak the data publicly if the ransom was not paid; in at least one case they did this. Many other gangs followed; "leak sites" were created on the dark web where stolen data could be accessed. Later attacks focussed on the threat to leak data, without necessarily locking it—this negated the protection afforded victims by robust backup procedures. As of 2023[update] there is a risk of hostile governments using ransomware to conceal what is actually intelligence gathering.[77]
The first reported death following a ransomware attack was at a German hospital in October 2020.[78]
There was a significant increase in ransomware attacks during the 2020COVID-19 pandemic. Evidence found that the targeted institutions of these attacks included government, finance, and healthcare. Researchers have contended that several different factors can explain the increase in attacks during this time. However, a major factor is thatremote work, which became the norm for many industries in 2020, led to the surge in attacks because of the lack of security in comparison to traditional work environments.[79]
Ransomware attacks are estimated to have led to payments totalling $1.1bn in 2019, $999m in 2020, and a record $1.25bn in 2023. This decreased to $813m in 2024, with a sharp drop in the second half of the year, according to research firmChainalysis, attributed to victims refusing to pay, and action by law enforcement. However, Chainalysis said that the downward trend in payments was fragile, and ransomware attacks remained prolific.[80] A coordinated international operation in February 2024 took down gangLockBit, and gangBlackCat/ALPHV disappeared.[80]
As of early 2015, the United Kingdom was considering banning schools, the NHS and local councils from making ransomware payments, requiring private companies to report proposed payouts, and requiring mandatory reporting of ransomware attacks.[80]
In 2012, a major ransomware Trojan known as Reveton began to spread. Based on the CitadelTrojan (which, itself, is based on theZeus Trojan), its payload displays a warning purportedly from a law enforcement agency claiming that the computer has been used for illegal activities, such as downloadingunlicensed software orchild pornography. Due to this behaviour, it is commonly referred to as the "Police Trojan".[81][82][83] The warning informs the user that to unlock their system, they would have to pay a fine using a voucher from an anonymous prepaid cash service such asUkash orpaysafecard. To increase the illusion that the computer is being tracked by law enforcement, the screen also displays the computer'sIP address, while some versions display footage from a victim'swebcam to give the illusion that the user is being recorded.[7][84]
Reveton initially began spreading in various European countries in early 2012.[7] Variants were localized with templates branded with the logos of different law enforcement organizations based on the user's country; for example, variants used in the United Kingdom contained the branding of organizations such as theMetropolitan Police Service and thePolice National E-Crime Unit. Another version contained the logo of theroyalty collection societyPRS for Music, which specifically accused the user of illegally downloading music.[85] In a statement warning the public about the malware, the Metropolitan Police clarified that they would never lock a computer in such a way as part of an investigation.[7][20]
In May 2012,Trend Micro threat researchers discovered templates for variations for theUnited States andCanada, suggesting that its authors may have been planning to target users in North America.[86] By August 2012, a new variant of Reveton began to spread in the United States, claiming to require the payment of a$200 fine to the FBI using aMoneyPak card.[8][9][84] In February 2013, a Russian citizen was arrested inDubai by Spanish authorities for his connection to a crime ring that had been using Reveton; ten other individuals were arrested onmoney laundering charges.[87] In August 2014,Avast Software reported that it had found new variants of Reveton that also distribute password-stealing malware as part of its payload.[88]
Encrypting ransomware reappeared in September 2013 with a Trojan known asCryptoLocker, which generated a 2048-bit RSA key pair and uploaded in turn to a command-and-control server, and used to encrypt files using awhitelist of specificfile extensions. The malware threatened to delete the private key if a payment ofBitcoin or a pre-paid cash voucher was not made within 3 days of the infection. Due to the extremely large key size it uses, analysts and those affected by the Trojan considered CryptoLocker extremely difficult to repair.[29][89][90][91] Even after the deadline passed, the private key could still be obtained using an online tool, but the price would increase to 10 BTC—which cost approximately US$2300 as of November 2013.[92][93]
CryptoLocker was isolated by the seizure of theGameover ZeuSbotnet as part ofOperation Tovar, as officially announced by theU.S. Department of Justice on 2 June 2014. The Department of Justice also publicly issued anindictment against the Russian hacker Evgeniy Bogachev for his alleged involvement in the botnet.[94][95] It was estimated that at least US$3 million was extorted with the malware before the shutdown.[12]
In September 2014, a wave of ransomware Trojans surfaced that first targeted users inAustralia, under the namesCryptoWall andCryptoLocker (which is, as with CryptoLocker 2.0, unrelated to the original CryptoLocker). The Trojans spread via fraudulent e-mails claiming to be failed parcel delivery notices fromAustralia Post; to evade detection by automatic e-mail scanners that follow all links on a page to scan for malware, this variant was designed to require users to visit a web page and enter aCAPTCHA code before the payload is actually downloaded, preventing such automated processes from being able to scan the payload.Symantec determined that these new variants, which it identified asCryptoLocker.F, were again, unrelated to the original CryptoLocker due to differences in their operation.[96][97] A notable victim of the Trojans was theAustralian Broadcasting Corporation; live programming on its televisionnews channelABC News 24 was disrupted for half an hour and shifted toMelbourne studios due to a CryptoWall infection on computers at itsSydney studio.[98][99][100]
Another Trojan in this wave,TorrentLocker, initially contained a design flaw comparable to CryptoDefense; it used the samekeystream for every infected computer, making the encryption trivial to overcome. However, this flaw was later fixed.[42] By late-November 2014, it was estimated that over 9,000 users had been infected by TorrentLocker in Australia alone, trailing only Turkey with 11,700 infections.[101]
Another major ransomware Trojan targeting Windows, CryptoWall, first appeared in 2014. One strain of CryptoWall was distributed as part of amalvertising campaign on theZedo ad network in late-September 2014 that targeted several major websites; the ads redirected to rogue websites that used browser pluginexploits[102] to download the payload. ABarracuda Networks researcher also noted that the payload was signed with adigital signature in an effort to appear trustworthy to security software.[103]CryptoWall 3.0 used a payload written inJavaScript as part of an email attachment, which downloads executables disguised asJPG images. To further evade detection, the malware creates new instances ofexplorer.exe andsvchost.exe to communicate with its servers. When encrypting files, the malware also deletes volume shadow copies and installs spyware that steals passwords andBitcoin wallets.[104]
The FBI reported in June 2015 that nearly 1,000 victims had contacted the bureau'sInternet Crime Complaint Center to report CryptoWall infections, and estimated losses of at least $18 million.[13]
The most recent[when?] version, CryptoWall 4.0, enhanced its code to avoid antivirus detection, and encrypts not only the data in files but also the file names.[105]
Fusob is a major family of mobile ransomware. Between April 2015 and March 2016, about 56 percent of accounted mobile ransomware was Fusob.[106]
Like most other pieces of ransomware, it employs scare tactics to extort a hefty sum from the user.[107] The appacts as if it were a notice from the authorities, demanding the victim to pay a fine from $100 to $200USD or otherwise face a fictitious criminal charge. Fusob requests iTunes gift cards for payment, unlike most cryptocurrency-centric ransomware.
In order to infect devices, Fusobmasquerades as a pornographic video player.[108] When it is installed, it first checks the device's system language. If the language is Russian or Eastern-European, Fusob remains dormant. Otherwise, it locks the device and demands ransom. About 40% of victims are in Germany, while the United Kingdom encompasses 14.5% of victims and the US encompasses 11.4%. Fusob and Small (another family of ransomware) represented over 93% of mobile ransomware between 2015 and 2016.
In May 2017, theWannaCry ransomware attack spread through the Internet, using an exploit vector namedEternalBlue, which was allegedly leaked from the U.S.National Security Agency. The ransomware attack, unprecedented in scale,[109] infected more than 230,000 computers in over 150 countries,[110] using 20 different languages to demand money from users usingBitcoin cryptocurrency. WannaCry demanded US$300 per computer.[111] The attack affectedTelefónica and several other large companies in Spain, as well as parts of the BritishNational Health Service (NHS), where at least 16 hospitals had to turn away patients or cancel scheduled operations,[112]FedEx,Deutsche Bahn,Honda,[113]Renault, as well as theRussian Interior Ministry and Russian telecomMegaFon.[114] The attackers gave their victims a 7-day deadline from the day their computers got infected, after which the encrypted files would be deleted.[115]
Petya was first discovered in March 2016; unlike other forms of encrypting ransomware, the malware aimed to infect themaster boot record, installing a payload which encrypts the file tables of theNTFS file system the next time that the infected system boots, blocking the system from booting into Windows at all until the ransom is paid.Check Point reported that despite what it believed to be an innovative evolution in ransomware design, it had resulted in relatively-fewer infections than other ransomware active around the same time frame.[116]
On 27 June 2017, a heavily modified version of Petya was used for a global cyberattack primarily targetingUkraine (but affecting many countries[117]). This version had been modified to propagate using the same EternalBlue exploit that was used by WannaCry. Due to another design change, it is also unable to actually unlock a system after the ransom is paid; this led to security analysts speculating that the attack was not meant to generate illicit profit, but to simply cause disruption.[118][119]
"Bad Rabbit" redirects here. For the band, seeBad Rabbits. For the computer worm, seeBadbunny.
On 24 October 2017, some users inRussia and Ukraine reported a new ransomware attack, named "Bad Rabbit", which follows a similar pattern to WannaCry and Petya by encrypting the user's file tables and then demands a Bitcoin payment to decrypt them.ESET believed the ransomware to have been distributed by a bogus update toAdobe Flash software.[120] Among agencies that were affected by the ransomware were:Interfax,Odesa International Airport,Kyiv Metro, and the Ministry of Infrastructure of Ukraine.[121] As it used corporate network structures to spread, the ransomware was also discovered in other countries, including Turkey, Germany, Poland, Japan, South Korea, and the United States.[122] Experts believed the ransomware attack was tied to the Petya attack in Ukraine (especially because Bad Rabbit's code has many overlapping and analogical elements to the code of Petya/NotPetya,[123] appending to CrowdStrike Bad Rabbit and NotPetya's dynamic link library (DLL) share 67 percent of the same code[124]) though the only identity to the culprits are the names of characters from theGame of Thrones series embedded within the code.[122]
Security experts found that the ransomware did not use the EternalBlue exploit to spread, and a simple method to inoculate an unaffected machine running older Windows versions was found by 24 October 2017.[125][126] Further, the sites that had been used to spread the bogus Flash updating have gone offline or removed the problematic files within a few days of its discovery, effectively killing off the spread of Bad Rabbit.[122]
Mohammad Mehdi Shah Mansouri (born inQom,Iran in 1991) and Faramarz Shahi Savandi (born inShiraz,Iran, in 1984) are wanted by theFBI for allegedly launching SamSam ransomware.[129] The two have allegedly made $6 million from extortion and caused over $30 million in damages using the malware.[130]
On May 7, 2021, a cyberattack was executed on the US Colonial Pipeline. TheFederal Bureau of Investigation identifiedDarkSide as the perpetrator of theColonial Pipeline ransomware attack, perpetrated bymalicious code, that led to a voluntary shutdown of the main pipeline supplying 45% of fuel to theEast Coast of the United States. The attack was described as the worst cyberattack to date on the U.S.critical infrastructure. DarkSide successfully extorted about 75Bitcoin (almost US$5 million) from Colonial Pipeline. U.S. officials are investigating whether the attack was purely criminal or took place with the involvement of the Russian government or another state sponsor. Following the attack, DarkSide posted a statement claiming that "We are apolitical, we do not participate ingeopolitics...Our goal is to make money and not creating problems for society."
In May 2021, the FBI andCybersecurity and Infrastructure Security Agency (CISA) issued a joint alert urging the owners and operators of critical infrastructure to take certain steps to reduce their vulnerability to DarkSide ransomware and ransomware in general.
Syskey is a utility that was included withWindows NT-based operating systems to encrypt theuser account database, optionally with a password. The tool has sometimes been effectively used as ransomware duringtechnical support scams—where a caller with remote access to the computer may use the tool to lock the user out of their computer with a password known only to them.[131] Syskey was removed from later versions ofWindows 10 andWindows Server in 2017, due to being obsolete and "known to be used by hackers as part of ransomware scams".[132][133]
Ransomware-as-a-service (RaaS) became a notable method after the Russia-based[134] or Russian-speaking[135] groupREvil staged operations against several targets, including the Brazil-basedJBS S.A. in May 2021, and the US-basedKaseya Limited in July 2021.[136] After a July 9, 2021 phone call between United States presidentJoe Biden and Russian presidentVladimir Putin, Biden told the press, "I made it very clear to him that the United States expects when a ransomware operation is coming from his soil even though it’s not sponsored by the state, we expect them to act if we give them enough information to act on who that is." Biden later added that the United States would take the group's servers down if Putin did not.[137][138] Four days later, REvil websites and other infrastructure vanished from the internet.[139]
If an attack is suspected or detected in its early stages, it takes some time for encryption to take place; immediate removal of the malware (a relatively simple process) before it has completed would stop further damage to data, without salvaging any already lost.[140][141]
Security experts have suggested precautionary measures for dealing with ransomware. Using software or other security policies to block known payloads from launching will help to prevent infection, but will not protect against all attacks[29][142] As such, having a properbackup solution is a critical component to defending against ransomware. Note that, because many ransomware attackers will not only encrypt the victim's live machine but it will also attempt to delete any hot backups stored locally or on accessible over the network on aNAS, it is also critical to maintain "offline"backups of datastored in locations inaccessible from any potentially infected computer, such as external storage drives or devices thatdo not have any access to any network (including the Internet), prevents them from being accessed by the ransomware. Moreover, if using a NAS orCloud storage, then the computer should haveappend-only permission to the destination storage, such that it cannot delete or overwrite previous backups. According tocomodo, applying twoAttack Surface Reduction onOS/Kernel provides a materially-reduced attack surface which results in a heightened security posture.[143][144][145]
Installing securityupdates issued by software vendors can mitigate thevulnerabilities leveraged by certain strains to propagate.[146][147][148][149][150] Other measures includecyber hygiene − exercising caution when openinge-mail attachments and links,network segmentation, and keeping critical computers isolated from networks.[151][152] Furthermore, to mitigate the spread of ransomware measures ofinfection control can be applied.[153] Such may include disconnecting infected machines from all networks, educational programs,[154] effective communication channels, malware surveillance[original research?] and ways of collective participation[153]
In August 2021, theCybersecurity and Infrastructure Security Agency (CISA) released a report that provided guidance for how to mitigate ransomware attacks. This was due to a significant jump in recent attacks related to ransomware. These attacks included aggression against a US pipeline company and a software company, which impacted the downstream customers ofMSPs.[155]
Write Once Read Many (WORM) storage, such as many optical disc formats are virtually immune to ransomware since its contents cannot be changed or deleted. However data cannot be deleted in any way making it impractical for many storage due to privacy laws and other content laws, the only way is to copy it to a new WORM disk minus the unwanted files, then destroy the original copy.
A number of file systems keep snapshots of the data they hold, which can be used to recover the contents of files from a time prior to the ransomware attack in the event the ransomware does not disable it.
On Windows, theVolume shadow copy (VSS) is often used to store backups of data; ransomware often targets these snapshots to prevent recovery and therefore it is often advisable to disable user access to the user toolVSSadmin.exe to reduce the risk that ransomware can disable or delete past copies.
On Windows 10, users can add specific directories or files to Controlled Folder Access in Windows Defender to protect them from ransomware.[156] It is advised to add backup and other important directories to Controlled Folder Access.
Unless malware gains root on the ZFS host system in deploying an attack coded to issue ZFS administrative commands, file servers runningZFS are broadly immune to ransomware, because ZFS is capable of snapshotting even a large file system many times an hour, and these snapshots are immutable (read only) and easily rolled back or files recovered in the event of data corruption.[157] In general, only an administrator can delete (but cannot modify) snapshots.
There are a number of tools intended specifically to decrypt files locked by ransomware, although successful recovery may not be possible.[2][158] If the same encryption key is used for all files, decryption tools use files for which there are both uncorrupted backups and encrypted copies (aknown-plaintext attack in the jargon ofcryptanalysis. But it only works when the cipher the attacker used was weak to begin with, being vulnerable to known-plaintext attack); recovery of the key, if it is possible, may take several days.[159] Free ransomware decryption tools can help decrypt files encrypted by the following forms of ransomware: AES_NI, Alcatraz Locker, Apocalypse, BadBlock, Bart, BTCWare, Crypt888, CryptoMix, CrySiS, EncrypTile, FindZip, Globe,Hidden Tear, Jigsaw, LambdaLocker, Legion, NoobCrypt, Stampado, SZFLocker,TeslaCrypt, XData.[160] Ransomware encryption that has been cracked by security researchers is typically abandoned for criminal purposes; thus in practice most attacks cannot be reverted by breaking encryption.[161]
In addition, old copies of files may exist on the disk, which has been previously deleted. In some cases, these deleted versions may still be recoverable usingsoftware designed for that purpose.
A 2019ProPublica investigation found the cybersecurity firms Proven Data Recovery and Monstercloud, which advertised ransom-free decryption services, would typically simply pay the ransom and charge the victim a higher price.[161] SamSam hackers dealt with Proven Data so frequently that they would recommend the company to victims having technical difficulties making payment.[161] Other companies like Coveware were more transparent in offering the service of paying the hackers and patching insecure systems.[161] Many American victims found the ransom amount was too low to meet theUnited States Department of Justice threshold for federal involvement, but that local police lacked the technical capabilities to help and were often victims themselves.[161]
A British student, Zain Qaiser, from Barking, London was jailed for more than six years atKingston upon Thames Crown Court for his ransomware attacks in 2019.[164] He is said to have been "the most prolific cyber criminal to be sentenced in the UK". He became active at the age of 17. He contacted the Russian controller of one of the most powerful attacks, believed to be the Lurk malware gang, and arranged for a split of his profits. He also contacted online criminals from China and the US to move the money.[164] For about one and a half years, he posed as a legitimate supplier of online promotions of book advertising on some of the world's most visited legal pornography websites. Each of the adverts that were promoted on the websites contained theReveton Ransomware strain of the malicious Angler Exploit Kit (AEK)[165] that seized control of the machine. Investigators discovered about £700,000 of earnings, although his network may have earned more than £4m. He may have hidden some money using cryptocurrencies. The ransomware would instruct victims to buyGreenDot MoneyPak vouchers and enter the code in the Reveton panel displayed on the screen. This money entered a MoneyPak account managed by Qaiser, who would then deposit the voucher payments into the debit card account of his American co-conspirator, Raymond Odigie Uadiale. Uadiale was a student atFlorida International University during 2012 and 2013 and later worked for Microsoft. Uadiale would convert the money intoLiberty Reserve digital currency and deposit it into Qaiser's Liberty Reserve account.[166]
A breakthrough, in this case, occurred in May 2013 when authorities from several countries seized the Liberty Reserve servers, obtaining access to all its transactions and account history. Qaiser was running encrypted virtual machines on his Macbook Pro with both Mac and Windows operating systems.[167] He could not be tried earlier because he was sectioned (involuntarily committed) under the UK Mental Health Act of 1983 atGoodmayes Hospital where he was found to be using the hospital Wi-Fi to access his advertising sites. His lawyer claimed that Qaiser had suffered from mental illness.[164] Russian police arrested 50 members of the Lurk malware gang in June 2016.[168] Uadiale, a naturalized US citizen of Nigerian descent, was jailed for 18 months.[169]
The publication of proof-of-concept attack code is common among academic researchers and vulnerability researchers.It teaches the nature of the threat, conveys the gravity of the issues, and enables countermeasures to be devised and put into place. However, lawmakers with the support of law-enforcement bodies are contemplating making the creation of ransomware illegal. In the state of Maryland, the original draft of HB 340 made it a felony to create ransomware, punishable by up to 10 years in prison.[170] A minor in Japan was arrested for creating and distributing ransomware code.[171]
^Adam Young (2005). Zhou, Jianying; Lopez, Javier (eds.). "Building a Cryptovirus Using Microsoft's Cryptographic API".Information Security: 8th International Conference, ISC 2005.Springer-Verlag. pp. 389–401.
^Young, Adam (2006). "Cryptoviral Extortion Using Microsoft's Crypto API: Can Crypto APIs Help the Enemy?".International Journal of Information Security.5 (2):67–76.doi:10.1007/s10207-006-0082-7.S2CID12990192.
^Al-Hawawreh, Muna; den Hartog, Frank; Sitnikova, Elena (2019). "Targeted Ransomware: A New Cyber Threat to Edge System of Brownfield Industrial Internet of Things".IEEE Internet of Things Journal.6 (4):7137–7151.doi:10.1109/JIOT.2019.2914390.S2CID155469264.
Yang, T.; Yang, Y.; Qian, K.; Lo, D.C.T.; Qian, L. & Tao, L. (2015).2015 IEEE 17th International Conference on High Performance Computing and Communications, 2015 IEEE 7th International Symposium on Cyberspace Safety and Security, and 2015 IEEE 12th International Conference on Embedded Software and Systems. IEEE Internet of Things Journal, CONFERENCE, AUGUST 2015. pp. 1338–1343.doi:10.1109/HPCC-CSS-ICESS.2015.39.ISBN978-1-4799-8937-9.S2CID5374328.
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