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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_5

Detects VEILEDSIGNAL malware

APT / threat actorVeiledsignalSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Mandiant
Date
2023-04-20
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Detects VEILEDSIGNAL malware

Associated malware family: Veiledsignal.

Targets: Windows PE.

It defines 10 patterns (9 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
apt-nk-mal-m-hunting-veiledsignal-5.yarDetection Rule License 1.1
rule SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_5 : FILE
{
	meta:
		description = "Detects VEILEDSIGNAL malware"
		author = "Mandiant"
		id = "7d0718fc-4f1c-5293-8dc4-81a5783fbfb2"
		date = "2023-04-20"
		modified = "2023-12-05"
		reference = "https://www.mandiant.com/resources/blog/3cx-software-supply-chain-compromise"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_nk_tradingtech_apr23.yar#L120-L143"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "6727284586ecf528240be21bb6e97f88"
		logic_hash = "5d43b8198ad224bee8d290dd7031d73f76a7d957a2e3b44d89e7aaf5f2c94c65"
		score = 75
		quality = 85
		tags = "FILE"
		disclaimer = "This rule is meant for hunting and is not tested to run in a production environment"

	strings:
		$sb1 = { 48 8D 15 [4] 48 8D 4C 24 4C E8 [4] 85 C0 74 ?? 48 8D 15 [4] 48 8D 4C 24 4C E8 [4] 85 C0 74 ?? 48 8D 15 [4] 48 8D 4C 24 4C E8 [4] 85 C0 74 ?? 48 8D [3] 48 8B CB FF 15 [4] EB }
		$ss1 = "chrome.exe" wide fullword
		$ss2 = "firefox.exe" wide fullword
		$ss3 = "msedge.exe" wide fullword
		$ss4 = "\\\\.\\pipe\\*" ascii fullword
		$ss5 = "FindFirstFileA" ascii fullword
		$ss6 = "Process32FirstW" ascii fullword
		$ss7 = "RtlAdjustPrivilege" ascii fullword
		$ss8 = "GetCurrentProcess" ascii fullword
		$ss9 = "NtWaitForSingleObject" ascii fullword

	condition:
		( uint16( 0 ) == 0x5A4D ) and ( uint32( uint32( 0x3C ) ) == 0x00004550 ) and ( uint16( uint32( 0x3C ) + 0x18 ) == 0x020B ) and all of them
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$sb1hex{ 48 8D 15 [4] 48 8D 4C 24 4C E8 [4] 85 C0 74 ?? 48 8D 15 [4] 48 8D 4C 24 4C E8 [4] 85 C0 74 ?? 48 8D 15 [4] 48 8D 4C 24 4C E8 [4] 85 C0 74 ?? 48 8D [3] 48 8B C …
$ss1text"chrome.exe"wide fullword
$ss2text"firefox.exe"wide fullword
$ss3text"msedge.exe"wide fullword
$ss4text"\\\\.\\pipe\\*"ascii fullword
$ss5text"FindFirstFileA"ascii fullword
$ss6text"Process32FirstW"ascii fullword
$ss7text"RtlAdjustPrivilege"ascii fullword
$ss8text"GetCurrentProcess"ascii fullword
$ss9text"NtWaitForSingleObject"ascii fullword

Condition

( uint16( 0 ) == 0x5A4D ) and ( uint32( uint32( 0x3C ) ) == 0x00004550 ) and ( uint16( uint32( 0x3C ) + 0x18 ) == 0x020B ) 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

Sample hashes

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

  • 6727284586ecf528240be21bb6e97f88

Licence & attribution

Author: Mandiant

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: 7d0718fc-4f1c-5293-8dc4-81a5783fbfb2

Metadata

disclaimerThis rule is meant for hunting and is not tested to run in a production environment

Tags:FILE

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