YARA · BlackBerry Research & Intelligence (via Open-Source-YARA-rules)
BLACKBERRY_Mal_Win32_Onyx_Strain_Chaos_Ransomware_2022
Detects Onyx Ransomware build off of Chaos Builder v4
- Author
- BlackBerry Threat Research
- Date
- 2022-05-10
- Modified
- 2022-07-07
- Score / Quality
- 75 / 85
What this rule detects
Detects Onyx Ransomware build off of Chaos Builder v4
Targets: Windows PE.
It defines 3 patterns (3 text, 0 hex, 0 regex). YARA modules used: pe.
Summary generated from the rule's metadata and condition.
Rule source
Includes the imports needed to compile it on its own.
import "pe"
rule BLACKBERRY_Mal_Win32_Onyx_Strain_Chaos_Ransomware_2022 : FILE
{
meta:
= "Detects Onyx Ransomware build off of Chaos Builder v4"
= "BlackBerry Threat Research"
= "8c30c316-9fd3-5ad9-aea1-d93229cd9ca1"
= "2022-05-10"
= "2022-07-07"
= "https://blogs.blackberry.com/en/2022/05/yashma-ransomware-tracing-the-chaos-family-tree"
= "https://github.com/mikesxrs/Open-Source-YARA-rules/blob/ec0056f767db98bf6d5fd63877ad51fb54d350e9/Blackberry/Mal_Win32_Onyx_Strain_Chaos_Ransomware_2022.yar#L3-L28"
= "N/A"
= "2df2f36167710a4de4ff3fda8036472b1972b4175a0d14f8b06e0ad045eb5038"
= 75
= 85
= "FILE"
= "This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team"
strings:
$s1 = "(?:[13]{1}[a-km-zA-HJ-NP-Z1-9]{26,33}|bc1[a-z0-9]{39,59})" wide
$s2 = "All of your files are currently encrypted by ONYX strain." wide
$s3 = "Inform your supervisors and stay calm!" wide
condition:
uint16( 0 ) == 0x5a4d and pe.data_directories [ pe.IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR ] . size != 0 and all of ( $s* )
}
Strings (3 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $s1 | text | "(?:[13]{1}[a-km-zA-HJ-NP-Z1-9]{26,33}|bc1[a-z0-9]{39,59})" | wide |
| $s2 | text | "All of your files are currently encrypted by ONYX strain." | wide |
| $s3 | text | "Inform your supervisors and stay calm!" | wide |
Condition
uint16( 0 ) == 0x5a4d and pe.data_directories [ pe.IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR ] . size != 0 and all of ( $s* )In plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- All patterns in ( $s* ) must match.
- Uses the pe module.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
Licence & attribution
Author: BlackBerry Threat Research
Source repository: BlackBerry Research & Intelligence (via Open-Source-YARA-rules) @ ec0056f767
Licence: Apache License 2.0 (stated in the rule's own meta)
“This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team”
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 8c30c316-9fd3-5ad9-aea1-d93229cd9ca1
Tags:FILE
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