Threat Signal Report

Destructive Onyx ransomware in the wild

description-logo Description

FortiGuard Labs is aware that a new ransomware "Onyx" is in the wild. The ransomware was first discovered in late April, 2022. The malware appears to be based on Chaos ransomware and overwrites files bigger than 2MB, making file recovery very difficult.

What is this Significant?

This is significant because the threat actor opted to have Onyx ransomware overwrite files bigger than 2MB on the compromised machine rather than encrypting them. Although the threat actor promises to decrypt the affected files after ransom payment is made, recovery of the overwritten files will be difficult.

What does Onyx Ransomware do?

The ransomware overwrites files bigger than 2MB on the compromised machine, encrypts files smaller than 2MB, and adds file extension ".ampkcz" to them. It also collects sensitive information such as credentials from the affected machine.

It then displays the following ransom message and demands ransom from the victim in order to recover the affected files:

"All of your files are currently encrypted by ONYX strain.

As you already know, all of your data has been encrypted by our software.

It cannot be recovered by any means without contacting our team directly.

DON'T TRY TO RECOVER your data by yourselves. Any attempt to recover your data (including the usage of the additional recovery software) can damage your files. However,

if you want to try - we recommend choosing the data of the lowest value.

DON'T TRY TO IGNORE us. We've downloaded a pack of your internal data and are ready to publish it on our news website if you do not respond.

So it will be better for both sides if you contact us as soon as possible.

DON'T TRY TO CONTACT feds or any recovery companies.

We have our informants in these structures, so any of your complaints will be immediately directed to us.

So if you will hire any recovery company for negotiations or send requests to the FBI, we will consider this as a hostile intent and initiate the publication of whole compromised data immediately.

To prove that we REALLY CAN get your data back - we offer you to decrypt two random files completely free of charge.

You can contact our team directly for further instructions through our website :


(you should download and install TOR browser first

style="font-style: italic;">http://[Removed}].onion

style="font-style: italic;">Login: [Removed]

Password: [Removed]


We will speak only with an authorized person. It can be the CEO, top management, etc.

In case you are not such a person - DON'T CONTACT US! Your decisions and action can result in serious harm to your company!

Inform your supervisors and stay calm!"

What is the Status of Coverage?

FortiGuard Labs provides the following AV detection for known Onyx ransomware samples:



Traffic Light Protocol

Color When Should it Be used? How may it be shared?


Not for disclosure, restricted to participants only.
Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused. Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.


Limited disclosure, restricted to participants’ organizations.
Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved. Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.


Limited disclosure, restricted to the community.
Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector. Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.


Disclosure is not limited.
Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.