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YARA · BlackBerry Research & Intelligence (via Open-Source-YARA-rules)

BLACKBERRY_Mal_Win32_Chaos_Builder_Ransomware_2022

Detects Chaos Ransomware Builder

MalwareBlackBerry Research & Intelligence (via Open-Source-YARA-rules)Apache License 2.0Compiles with YARA-X
Author
BlackBerry Threat Research
Date
2022-05-10
Modified
2022-07-08
Score / Quality
75 / 85

What this rule detects

Detects Chaos Ransomware Builder

Targets: Windows PE.

It defines 7 patterns (7 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
mal-win32-chaos-builder-ransomware-2022.yarApache License 2.0
rule BLACKBERRY_Mal_Win32_Chaos_Builder_Ransomware_2022 : FILE
{
	meta:
		description = "Detects Chaos Ransomware Builder"
		author = "BlackBerry Threat Research"
		id = "53c812da-802c-5116-89aa-455d1a20a179"
		date = "2022-05-10"
		modified = "2022-07-08"
		reference = "https://blogs.blackberry.com/en/2022/05/yashma-ransomware-tracing-the-chaos-family-tree"
		source_url = "https://github.com/mikesxrs/Open-Source-YARA-rules/blob/ec0056f767db98bf6d5fd63877ad51fb54d350e9/Blackberry/Mal_Win32_Chaos_Builder_Ransomware_2022.yar#L4-L44"
		license_url = "N/A"
		logic_hash = "32b68ef2f6e011255080f2666170a4fad42c6a8dd28a05c1a58936dcd27084ec"
		score = 75
		quality = 85
		tags = "FILE"
		license = "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:
		$s0 = "1qw0ll8p9m8uezhqhyd" ascii wide
		$s1 = "Chaos Ransomware Builder" ascii wide
		$s2 = "payloadFutureName" ascii wide
		$s3 = "read_it.txt" ascii wide
		$s4 = "encryptedFileExtension" ascii wide
		$x0 = "1098576" ascii wide
		$x1 = "2197152" ascii wide

	condition:
		uint16( 0 ) == 0x5a4d and ( ( all of ( $s* ) ) and ( 1 of ( $x* ) ) )
}

Strings (7 patterns)

IdentifierTypeValueModifiers
$s0text"1qw0ll8p9m8uezhqhyd"ascii wide
$s1text"Chaos Ransomware Builder"ascii wide
$s2text"payloadFutureName"ascii wide
$s3text"read_it.txt"ascii wide
$s4text"encryptedFileExtension"ascii wide
$x0text"1098576"ascii wide
$x1text"2197152"ascii wide

Condition

uint16( 0 ) == 0x5a4d and ( ( all of ( $s* ) ) and ( 1 of ( $x* ) ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in ( $s* ) must match.
  • At least 1 patterns in ( $x* ) must match.

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References

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”

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: 53c812da-802c-5116-89aa-455d1a20a179

Tags:FILE

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