Posted: 3 Min ReadThreat Intelligence

RansomHub: New Ransomware has Origins in Older Knight

Emergent operation has grown quickly to become one of the most prolific ransomware threats

RansomHub, a new Ransomware-as-a-Service (RaaS) that has rapidly become one of the largest ransomware groups currently operating, is very likely an updated and rebranded version of the older Knight ransomware. 

Analysis of the RansomHub payload by Symantec, part of Broadcom, revealed a high degree of similarity between the two threats, suggesting that Knight was the starting point for RansomHub. 

Despite shared origins, it is unlikely that Knight’s creators are now operating RansomHub. Source code for Knight (originally known as Cyclops) was offered for sale on underground forums in February 2024 after Knight’s developers decided to shut down their operation. It is possible that other actors bought the Knight source code and updated it before launching RansomHub. 

RansomHub and Knight compared

Both payloads are written in Go and most variants of each family are obfuscated with Gobfuscate.  Only some early versions of Knight are not obfuscated. 

The degree of code overlap between the two families is significant, making it very difficult to differentiate between them.  In many cases, a determination could only be confirmed by checking the embedded link to the data leak site.

The two families have virtually identical help menus available on the command line. The sole difference is the addition of a sleep command in RansomHub.

Figure 1. Knight command-line help menu.
Figure 1. Knight command-line help menu.
Figure 2. RansomHub command-line help menu.
Figure 2. RansomHub command-line help menu.

Both threats employ a unique obfuscation technique, where important strings are each encoded with a unique key and decoded at runtime. For example, in the command “cmd.exe /c iisreset.exe /stop”, only the iisrest.exe string is encrypted with a unique key.

Figure 3. RansomHub string encoding. Only the iisrest.exe string is encrypted with a unique key.
Figure 3. RansomHub string encoding. Only the iisrest.exe string is encrypted with a unique key.

There are significant similarities between the ransom notes left by both payloads, with many phrases used by Knight appearing verbatim in the RansomHub note, suggesting that the developers simply edited and updated the original note.

Figure 4. Knight ransom note.
Figure 4. Knight ransom note.
Figure 5. RansomHub ransom note.
Figure 5. RansomHub ransom note.

One of the main differences between the two ransomware families is the commands run through cmd.exe. These commands may be configured when the payload is built or during configuration.  Although the commands themselves are different, the way and order in which they are called relative to other operations is the same.  

A unique feature present in both Knight and RansomHub is the ability to restart an endpoint in safe mode before starting encryption. This technique was previously employed by Snatch ransomware in 2019 and allows encryption to progress unhindered by operating system or other security processes. Snatch is also written in Go and has many similar features, suggesting it could be another fork of the same original source code used to develop Knight and RansomHub. However, Snatch contains significant differences, including an apparent lack of configurable commands or any sort of obfuscation.

Another ransomware family that restarts the affected computer in safe mode before encryption is Noberus Interestingly, the encryptor stores its configuration in a JSON where keywords match what was observed in RansomHub.

RansomHub attacks

In recent RansomHub attacks investigated by Symantec, the attackers gained initial access by exploiting the Zerologon vulnerability (CVE-2020-1472), which can allow an attacker to gain domain administrator privileges and take control of the entire domain.

The attackers used several dual-use tools before deploying the ransomware. Atera and Splashtop were used to facilitate remote access, while NetScan was used to likely discover and retrieve information about network devices. The RansomHub payload leveraged the iisreset.exe and iisrstas.exe command-line tools to stop all Internet Information Services (IIS) services. 

Rapid growth

Despite only first appearing in February 2024, RansomHub has managed to grow very quickly and, over the past three months, was the fourth most prolific ransomware operator in terms of numbers of attacks publicly claimed. The group last week claimed responsibility for an attack on UK auction house Christies

Figure 6. Most prolific ransomware operations by claimed attacks, March-May 2023.
Figure 6. Most prolific ransomware operations by claimed attacks, March-May 2023.

One factor contributing to RansomHub’s growth may be the group’s success in attracting some large former affiliates of the Noberus (aka ALPHV, Blackcat) ransomware group, which closed earlier this year. One former Noberus affiliate known as Notchy is now reportedly working with RansomHub. In addition to this, tools previously associated with another Noberus affiliate known as Scattered Spider, were used in a recent RansomHub attack.

The speed at which RansomHub has established its business suggests that the group may consist of veteran operators with experience and contacts in the cyber underground.


For the latest protection updates, please visit the Symantec Protection Bulletin.

Indicators of Compromise

If an IOC is malicious and the file is available to us, Symantec Endpoint products will detect and block that file.

SHA-256 hash Description
02e9f0fbb7f3acea4fcf155dc7813e15c1c8d1c77c3ae31252720a9fa7454292 RansomHub
34e479181419efd0c00266bef0210f267beaa92116e18f33854ca420f65e2087 RansomHub
7539bd88d9bb42d280673b573fc0f5783f32db559c564b95ae33d720d9034f5a RansomHub
8f59b4f0f53031c555ef7b2738d3a94ed73568504e6c07aa1f3fa3f1fd786de7 RansomHub
ea9f0bd64a3ef44fe80ce1a25c387b562a6b87c4d202f24953c3d9204386cf00 RansomHub
104b22a45e4166a5473c9db924394e1fe681ef374970ed112edd089c4c8b83f2 Knight
2f3d82f7f8bd9ff2f145f9927be1ab16f8d7d61400083930e36b6b9ac5bbe2ad Knight
36e5be9ed3ec960b40b5a9b07ba8e15d4d24ca6cd51607df21ac08cda55a5a8e Knight
595cd80f8c84bc443eff619add01b86b8839097621cdd148f30e7e2214f2c8cb Knight
7114288232e469ff368418005049cf9653fe5c1cdcfcd63d668c558b0a3470f2 Knight
e654ef69635ab6a2c569b3f8059b06aee4bce937afb275ad4ec77c0e4a712f23 Knight
fb9f9734d7966d6bc15cce5150abb63aadd4223924800f0b90dc07a311fb0a7e NetScan
f1a6e08a5fd013f96facc4bb0d8dfb6940683f5bdfc161bd3a1de8189dea26d3 Splashtop
a96a0ba7998a6956c8073b6eff9306398cc03fb9866e4cabf0810a69bb2a43b2 Atera

About the Author

Threat Hunter Team


The Threat Hunter Team is a group of security experts within Symantec whose mission is to investigate targeted attacks, drive enhanced protection in Symantec products, and offer analysis that helps customers respond to attacks.

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