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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_CN_Twistedpanda_Droppers

Detects droppers used by TwistedPanda

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Check Point Research
Date
2022-04-14
Modified
2025-07-01
Score / Quality
80 / 85

What this rule detects

Detects droppers used by TwistedPanda

Targets: Windows PE.

It defines 6 patterns (0 text, 6 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
apt-cn-twistedpanda-droppers.yarDetection Rule License 1.1
rule SIGNATURE_BASE_APT_CN_Twistedpanda_Droppers : FILE
{
	meta:
		description = "Detects droppers used by TwistedPanda"
		author = "Check Point Research"
		id = "f61c8b97-5870-5837-942f-f1650870960a"
		date = "2022-04-14"
		modified = "2025-07-01"
		reference = "https://research.checkpoint.com/2022/twisted-panda-chinese-apt-espionage-operation-against-russians-state-owned-defense-institutes/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_cn_twisted_panda.yar#L157-L194"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "59dea38da6e515af45d6df68f8959601e2bbf0302e35b7989e741e9aba2f0291"
		hash = "8b04479fdf22892cdfebd6e6fbed180701e036806ed0ddbe79f0b29f73449248"
		hash = "f29a0cda6e56fc0e26efa3b6628c6bcaa0819a3275a10e9da2a8517778152d66"
		logic_hash = "820b4796511dcf98cdc8017a39cc2c65e44d8d9a20f55803aa1ddd36f649c83a"
		score = 80
		quality = 85
		tags = "FILE"

	strings:
		$switch_control = { 81 FA [4] 75 ?? E8 [4] 48 89 05 [4] E? }
		$byte_manipulation = { 41 0F [2] 44 [2] 41 [2] 03 41 81 [5] 41 }
		$stack_strings_1 = { 25 00 70 00 }
		$stack_strings_2 = { 75 00 62 00 }
		$stack_strings_3 = { 6C 00 69 00 }
		$stack_strings_4 = { 63 00 25 00 }

	condition:
		uint16( 0 ) == 0x5A4D and uint32( uint32( 0x3C ) ) == 0x00004550 and filesize < 3000KB and #switch_control > 8 and all of ( $stack_strings_* ) and $byte_manipulation
}

Strings (6 patterns)

IdentifierTypeValueModifiers
$switch_controlhex{ 81 FA [4] 75 ?? E8 [4] 48 89 05 [4] E? }
$byte_manipulationhex{ 41 0F [2] 44 [2] 41 [2] 03 41 81 [5] 41 }
$stack_strings_1hex{ 25 00 70 00 }
$stack_strings_2hex{ 75 00 62 00 }
$stack_strings_3hex{ 6C 00 69 00 }
$stack_strings_4hex{ 63 00 25 00 }

Condition

uint16( 0 ) == 0x5A4D and uint32( uint32( 0x3C ) ) == 0x00004550 and filesize < 3000KB and #switch_control > 8 and all of ( $stack_strings_* ) and $byte_manipulation

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 3000KB (a cheap guard that skips large files).
  • All patterns in ( $stack_strings_* ) must match.
  • Pattern $switch_control must occur > 8 times.
  • Pattern $byte_manipulation must be present.

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References

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

  • 59dea38da6e515af45d6df68f8959601e2bbf0302e35b7989e741e9aba2f0291
  • 8b04479fdf22892cdfebd6e6fbed180701e036806ed0ddbe79f0b29f73449248
  • f29a0cda6e56fc0e26efa3b6628c6bcaa0819a3275a10e9da2a8517778152d66

Licence & attribution

Author: Check Point Research

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: f61c8b97-5870-5837-942f-f1650870960a

Tags:FILE

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