The Relight films are a condensed version of the anime series. The premise of the films is that Ryuk tells the story to a fellow Shinigami. Light was gonna use that thing to make himself god of the New World. Doesn't that interest you?” ( L: Change the WorLd) Ryuk has a great fondness for apples, stating the addiction to be an equivalent of cigarettes and alcohol for humans. Shinigami apples are withered and taste like sand, as he shows Misa at one point, which is why he prefers apples from the human world. He suffers certain symptoms of withdrawal if he goes too long without eating them, involving twisting himself up like a pretzel and doing handstands. He also states that he is shy around girls, revealed when Misa regains her memories and hugs Ryuk in excitement. The encryption of local and mapped drives is done in 6 rounds. On each of these rounds, Ryuk will enumerate all the drives from A: to Z: and will then encrypt drives based on their types, which it gets using the GetDriveTypeA API. These are the drive types which will be encrypted on each round:

There are two types of Ryuk binaries: a dropper (which is not commonly observed) and the Ryuk executable payload. Recovery of Ryuk droppers are rare, due to the Ryuk executable payload deleting the dropper when executed. Upon execution, the dropper constructs an installation folder path. The folder path is created by calling GetWindowsDirectoryW and then inserting a null byte at the fourth character of the path. This is used to create a string that contains the drive letter path. If the host operating system is Windows XP or earlier, the string Documents and Settings\Default User\ is appended to the drive letter path. If the host is Windows Vista or newer, the string users\Public\ is appended to the drive letter path. For Windows XP, an example folder path would be C:\Documents and Settings\Default User\ , and for Window Vista or higher, the path would be C:\Users\Public . It feels sturdy and well-made, with no loose parts or wobbliness. The materials used seem durable, ensuring that it will withstand the test of time and retain its quality even after prolonged display. In the film series, Ryuk is very similar to his canon self. The second film ends in much the same manner as the manga, except Ryuk pretends to be more cooperative by laughing together with Light over the fact that the Task Force can't shoot through his incorporeal form. Ryuk informs Light that humans who have used the Death Note are unable to enter either Heaven or Hell and shows Light his name written in the notebook. Light yells at Ryuk and jumps through him, trying in vain to stop his death, before dying in his father's arms. After Light's death, Ryuk asks L if he will to use the Death Note, and when L says that he won't, Ryuk calls L boring and flies away. He is last seen several months later, laughing and circling around Tokyo Tower. Ryuk deliberately writes the instructions inside the front cover of the Death Note (in English, which he assumed to be the most popular language in the Human World) so people would understand its purpose. The Death Note is discovered by Light, and Ryuk follows him around for much of the series to see how Light uses it. You have lost, Light. Didn't I say in the beginning… when you die, the one who'll write your name down in a notebook will be me. That is… the deal between the Shinigami… and the first human to get their hands on the note in the human world. Once you enter the prison, I don't know when you'll die. It's annoying to wait… Your life is already over. You'll die here. Well, it was good while it lasted… We killed some boredom, didn't we? We did some various and interesting things…” ( Episode 37)Hermes ransomware, the predecessor to Ryuk, was first distributed in February 2017. Only one month after its release, a decryptor was written for Hermes, followed by the release of version 2.0 in April 2017, which fixed vulnerabilities in its cryptographic implementation. Since this release, the only way for a victim to recover files is with the private encryption key, which is obtained by paying the ransom. In late August 2017, Hermes version 2.1 was released. Disable the windows error recovery screen that appears during boot in case Windows was shut down improperly using: If executed on a 64 bit system, it will append the string by adding “/reg:64” to the command. This exact persistence method was used by previous samples as well. Wake-up Network Devices I was the whole thing, Taro. That was some pretty smart thinking. Hyuk hyuk hyuk. So how was it… the Land of the Dead?” ( Pilot chapter) Chaos started as a relatively basic attempt at a .NET compiled ransomware that instead functioned as a file-destructor or wiper. Over time it has evolved to become a full-fledged ransomware, adding additional features and functionality with each iteration.

As a passionate anime lover myself, with Death Note ranking among my all-time favorite series, I have had the pleasure of owning the SFC Figurine of Ryuk for some time now. Standing at an impressive 30 cm tall, this figurine not only captures the essence of Ryuk's character from Death Note but also satisfies the discerning tastes of dedicated anime enthusiasts like myself. Open-source reporting has claimed that the Hermes ransomware was developed by the North Korean group STARDUST CHOLLIMA (activities of which have been public reported as part of the “Lazarus Group”), because Hermes was executed on a host during the SWIFT compromise of FEIB in October 2017. Table 1 contains samples that are possibly attributed to the compromise. The two executables related to Hermes are bitsran.exe and RSW7B37.tmp .

Technical Analysis of Ryuk

Current builds of Ryuk no longer contain persistence functionality. Previously, to remain persistent on the host, Ryuk created a registry entry under the Run key using Windows cmd.exe shell. The following command line was used to write to the Registry Run Key name svchos to HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run with the value being the path to the Ryuk executable. Process Injection Ryuk regards Light as "interesting," specifically due to his experiments and the loopholes he discovers regarding the Death Note's rules and instructions, occasionally discovering abilities of the notebook even Ryuk did not know existed. Though he finds Light interesting, he does not care whether Light lives or dies and does not actively assist him. At times, he withholds important information from Light and only assists him when he has something to gain from it. As his only purpose in dropping the notebook was because he was bored, most of his actions are primarily motivated by wanting to see something interesting, as he sees Light's use of the Death Note and the way humans react to it as truly entertaining. Ryuk is intelligent, but Light's ability to understand his desires easily makes him able to be manipulated.

Though Chaos v4.0 had been in-the-wild for several months now, this variant of Chaos rose to notoriety in April 2022 when it was weaponized by a threat group called Onyx.

Introduction of Ryuk

CrowdStrike has observed another batch file, named windows.bat , which makes file recovery more difficult on the victim’s machine. It should be noted that file names can be arbitrarily changed by the threat actors. The contents of the batch file are shown below in Figure 2. You have lost, Light. Didn’t I say in the beginning, when you die, the one who’ll write your name down in a notebook will be me? That is the deal between the Shinigami and the first human to get their hands on the note in the human world. Once you enter prison, I don’t know when you’ll die. It’s annoying to wait. Your life is already over. You’ll die here.

The host discovery algorithm works in two stages. First, the sample attempts to discover which subnets the machine is connected to, and during the second stage it scans the subnet.The batch file kill.bat contains commands for stopping services, disabling services and killing processes. The processes and services are stopped to ensure no open handles exist for files that will be encrypted. The following figure is a subset of each command. This fact indicates that operators behind Ryuk malware carefully study each victim and perform expensive scouting and network mapping.