Ransomware

A Ransomware is a malware that holds the victim's data hostage.

• Context:
  • It can be detected by a Ransomware Detection System (that solves a ransomware detection task).
  • …
• Example(s):
  • WannaCry.
  • …
• See: Cryptovirology, Scareware, Computational Complexity Theory#Intractability, Key (Cryptography), Trojan Horse (Computing), Russia, Security Software.

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References

2022

• (Wikipedia, 2022) ⇒ https://en.wikipedia.org/wiki/ransomware Retrieved:2022-7-13.
  • Ransomware is a type of malware from crypto virology that threatens to publish the victim's personal data or perpetually block access to it unless a ransom is paid. While some simple ransomware may lock the system without damaging any files, more advanced malware uses a technique called cryptoviral extortion. It encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them. In a properly implemented cryptoviral extortion attack, recovering the files without the decryption key is an intractable problem – and difficult to trace digital currencies such as paysafecard or Bitcoin and other cryptocurrencies are used for the ransoms, making tracing and prosecuting the perpetrators difficult.

    Ransomware attacks are typically carried out using a Trojan 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, the WannaCry worm, traveled automatically between computers without user interaction.

    Starting as early as 1989 with the first documented ransomware known as the AIDS trojan, the use of ransomware scams has grown internationally. There were 181.5 million ransomware attacks in the first six months of 2018. This record marks a 229% increase over this same time frame in 2017. In June 2014, vendor McAfee released data showing that it had collected more than double the number of ransomware samples that quarter than it had in the same quarter of the previous year. CryptoLocker was particularly successful, procuring an estimated US$3 million before it was taken down by authorities, and CryptoWall was estimated by the US Federal Bureau of Investigation (FBI) to have accrued over US$18 million by June 2015. In 2020, the IC3 received 2,474 complaints identified as ransomware with adjusted losses of over $29.1 million. The losses could be more than that, according to the FBI. According to a report by SonicWall, there were around 623 million ransomware attacks in 2021.

2017

• (Wikipedia, 2017) ⇒ https://en.wikipedia.org/wiki/Ransomware Retrieved:2017-5-12.
  • Ransomware is computer malware that installs covertly on a victim's device (e.g., computer, smartphone, wearable device) and that either mounts the cryptoviral extortion attack from cryptovirology that holds the victim's data hostage, or mounts a cryptovirology leakware attack that threatens to publish the victim's data, until a ransom is paid. Simple ransomware may lock the system in a way which is not difficult for a knowledgeable person to reverse, and display a message requesting payment to unlock it. More advanced malware encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them. The ransomware may also encrypt the computer's Master File Table (MFT) or the entire hard drive. Thus, ransomware is a denial-of-access attack that prevents computer users from accessing files since it is intractable to decrypt the files without the decryption key. Ransomware attacks are typically carried out using a Trojan that has a payload disguised as a legitimate file. While initially popular in Russia, the use of ransomware scams has grown internationally; in June 2013, security software vendor McAfee released data showing that it had collected over 250,000 unique samples of ransomware in the first quarter of 2013, more than double the number it had obtained in the first quarter of 2012. Wide-ranging attacks involving encryption-based ransomware began to increase through Trojans such as CryptoLocker, which had procured an estimated US$3 million before it was taken down by authorities, and CryptoWall, which was estimated by the US Federal Bureau of Investigation (FBI) to have accrued over $18m by June 2015.

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