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SEKOIA_Apt_Apt_K_47_Walkershell

Detects WalkerShell used by APT-K-47

APT / threat actorSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2024-02-14
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detects WalkerShell used by APT-K-47

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

apt-apt-k-47-walkershell.yarDetection Rule License 1.1
rule SEKOIA_Apt_Apt_K_47_Walkershell : FILE
{
	meta:
		description = "Detects WalkerShell used by APT-K-47"
		author = "Sekoia.io"
		id = "201f8415-32d4-4af1-ba80-734554ced728"
		date = "2024-02-14"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_apt_k_47_walkershell.yar#L1-L20"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "0dffd8e4d6c244a4faea0f8b8cda1e544a732ad9982e7963b21d5f71080f8f5d"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$s1 = "\\n kuskure" ascii wide
		$s2 = "col.log.txt" ascii wide
		$s3 = "polor" ascii wide
		$s4 = "emit" ascii wide
		$s5 = "delta" ascii wide
		$s6 = "under process" ascii wide

	condition:
		uint16be( 0 ) == 0x4d5a and filesize < 4MB and all of them
}

Strings (6 patterns)

IdentifierTypeValueModifiers
$s1text"\\n kuskure"ascii wide
$s2text"col.log.txt"ascii wide
$s3text"polor"ascii wide
$s4text"emit"ascii wide
$s5text"delta"ascii wide
$s6text"under process"ascii wide

Condition

uint16be( 0 ) == 0x4d5a and filesize < 4MB and all of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 4MB (a cheap guard that skips large files).
  • All patterns in the rule must match.

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References

Licence & attribution

Author: Sekoia.io

Source repository: SEKOIA.IO Community @ a438a5901a

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: 201f8415-32d4-4af1-ba80-734554ced728

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE