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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_MAL_Tinyturla_Sep21_1

Detects Tiny Turla backdoor DLL

APT / threat actorTiny TurlaSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Cisco Talos
Date
2021-09-21
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Detects Tiny Turla backdoor DLL

Associated malware family: Tiny Turla.

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

apt-mal-tinyturla-sep21-1.yarDetection Rule License 1.1
rule SIGNATURE_BASE_APT_MAL_Tinyturla_Sep21_1 : FILE
{
	meta:
		description = "Detects Tiny Turla backdoor DLL"
		author = "Cisco Talos"
		id = "19659ac7-310a-52dd-a94c-022c7add752b"
		date = "2021-09-21"
		modified = "2023-12-05"
		reference = "https://blog.talosintelligence.com/2021/09/tinyturla.html"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_turla.yar#L275-L295"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "030cbd1a51f8583ccfc3fa38a28a5550dc1c84c05d6c0f5eb887d13dedf1da01"
		logic_hash = "ede598374bc4a8a870aa29498be4200b4a3d7b289dfcb680fb3f91108d212bca"
		score = 75
		quality = 85
		tags = "FILE"

	strings:
		$a = "Title: " fullword wide
		$b = "Hosts" fullword wide
		$c = "Security" fullword wide
		$d = "TimeLong" fullword wide
		$e = "TimeShort" fullword wide
		$f = "MachineGuid" fullword wide
		$g = "POST" fullword wide
		$h = "WinHttpSetOption" fullword ascii
		$i = "WinHttpQueryDataAvailable" fullword ascii

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 25KB and all of them
}

Strings (9 patterns)

IdentifierTypeValueModifiers
$atext"Title: "fullword wide
$btext"Hosts"fullword wide
$ctext"Security"fullword wide
$dtext"TimeLong"fullword wide
$etext"TimeShort"fullword wide
$ftext"MachineGuid"fullword wide
$gtext"POST"fullword wide
$htext"WinHttpSetOption"fullword ascii
$itext"WinHttpQueryDataAvailable"fullword ascii

Condition

uint16( 0 ) == 0x5a4d and filesize < 25KB and all of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 25KB (a cheap guard that skips large files).
  • 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).

  • 030cbd1a51f8583ccfc3fa38a28a5550dc1c84c05d6c0f5eb887d13dedf1da01

Licence & attribution

Author: Cisco Talos

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: 19659ac7-310a-52dd-a94c-022c7add752b

Tags:FILE

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