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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_MAL_APT_NK_Trifaux_Easyrat_JUPITER

Detects a variant of the EasyRAT malware family

MalwareJupiterSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
CISA.gov
Date
2024-07-25
Modified
2026-01-29
Score / Quality
80 / 85

What this rule detects

Detects a variant of the EasyRAT malware family

Associated malware family: Jupiter.

Targets: Windows PE.

It defines 3 patterns (2 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
mal-apt-nk-trifaux-easyrat-jupiter.yarDetection Rule License 1.1
rule SIGNATURE_BASE_MAL_APT_NK_Trifaux_Easyrat_JUPITER : FILE
{
	meta:
		description = "Detects a variant of the EasyRAT malware family"
		author = "CISA.gov"
		id = "8bd72287-59da-53cf-9015-66149303e59f"
		date = "2024-07-25"
		modified = "2026-01-29"
		reference = "https://www.cisa.gov/news-events/cybersecurity-advisories/aa24-207a"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_nk_andariel_jul24.yar#L44-L59"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "6108035dbebd34fe994fc1f8b4123321321f6ed5c022be6e84a88f905ea6fb73"
		score = 80
		quality = 85
		tags = "FILE"

	strings:
		$InitOnce = "InitOnceExecuteOnce"
		$BREAK = { 0D 00 0A 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 0D 00 0A }
		$Bytes = "4C,$00,$00,$00,$01,$14,$02,$00,$00,$00,$00,$00,$C0,$00,$00,$00,$00,$00,$00," wide

	condition:
		uint16( 0 ) == 0x5a4d and all of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$InitOncetext"InitOnceExecuteOnce"
$BREAKhex{ 0D 00 0A 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D 00 2D …
$Bytestext"4C,$00,$00,$00,$01,$14,$02,$00,$00,$00,$00,$00,$C0,$00,$00,$00,$00,$00,$00,"wide

Condition

uint16( 0 ) == 0x5a4d and all of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in the rule must match.

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References

Licence & attribution

Author: CISA.gov

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

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

Rule id: 8bd72287-59da-53cf-9015-66149303e59f

Tags:FILE

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