YARA · SEKOIA.IO Community

SEKOIA_Apt_Kimsuky_Sharptongue_Strings

Detects SharpTongue variants.

APT / threat actorKimsukySEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X

Author: Sekoia.io
Date: 2022-07-29
Modified: 2024-12-19
Score / Quality: 75 / 80

What this rule detects

Detects SharpTongue variants.

Associated malware family: Kimsuky.

It defines 4 patterns (4 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-kimsuky-sharptongue-strings.yarDetection Rule License 1.1

rule SEKOIA_Apt_Kimsuky_Sharptongue_Strings : FILE
{
	meta:
		description = "Detects SharpTongue variants."
		author = "Sekoia.io"
		id = "56027edb-4e6e-40ec-a1b9-36c52b0dd3ec"
		date = "2022-07-29"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_kimsuky_sharptongue_strings.yar#L1-L18"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "a7a9045485f6e713a8ae1bc87cd1296d64905b18e5d13d6e2b9a95328181af54"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$s1 = "Post0.Open" ascii wide
		$s2 = ".php?op=" ascii wide
		$s3 = "s=s&Mid(c,ix*d+jx+1,1)" ascii wide
		$s4 = "curl -o " ascii wide

	condition:
		$s2 in ( @s1 .. @s1 + 200 ) or $s2 in ( @s4 .. @s4 + 200 ) or $s3 and filesize < 500KB
}

Strings (4 patterns)

Identifier	Type	Value	Modifiers
$s1	text	"Post0.Open"	ascii wide
$s2	text	".php?op="	ascii wide
$s3	text	"s=s&Mid(c,ix*d+jx+1,1)"	ascii wide
$s4	text	"curl -o "	ascii wide

Condition

$s2 in ( @s1 .. @s1 + 200 ) or $s2 in ( @s4 .. @s4 + 200 ) or $s3 and filesize < 500KB

In plain words (Heuristic)

The file must be smaller than 500KB (a cheap guard that skips large files).
Pattern $s2 must be found within the range @s1 .. @s1 + 200.
Pattern $s2 must be found within the range @s4 .. @s4 + 200.
Pattern $s3 must be present.

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References

https://github.com/SEKOIA-IO/Community

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: 56027edb-4e6e-40ec-a1b9-36c52b0dd3ec

Metadata

version	1.0
classification	TLP:CLEAR

Tags:FILE

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