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SEKOIA_Apt_Konni_Dropper

Detects Konni dropper used when distributed via malicious document

APT / threat actorKonniSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2023-11-27
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detects Konni dropper used when distributed via malicious document

Associated malware family: Konni.

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

Summary generated from the rule's metadata and condition.

Rule source

apt-konni-dropper.yarDetection Rule License 1.1
rule SEKOIA_Apt_Konni_Dropper : FILE
{
	meta:
		description = "Detects Konni dropper used when distributed via malicious document"
		author = "Sekoia.io"
		id = "0783a55e-1d1e-40ca-a661-2c5dec6d78d6"
		date = "2023-11-27"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_konni_dropper.yar#L1-L19"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "6d1b1f5ccbdc20908891e5f40ceb85c251b1ca2a395fa4b106e63718c6393a22"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = "UnzipAFile"
		$ = "check.bat"
		$ = "FOF_SILENT"
		$ = "fLieObj"

	condition:
		filesize < 1MB and 3 of them
}

Strings (4 patterns)

IdentifierTypeValueModifiers
$text"UnzipAFile"
$text"check.bat"
$text"FOF_SILENT"
$text"fLieObj"

Condition

filesize < 1MB and 3 of them

In plain words (Heuristic)

  • The file must be smaller than 1MB (a cheap guard that skips large files).
  • At least 3 patterns in the rule must match.

Test this rule in your browser

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Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.

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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: 0783a55e-1d1e-40ca-a661-2c5dec6d78d6

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE

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