YARA · Volexity threat-intel

VOLEXITY_Apt_Malware_Charmingcypress_Openvpn_Configuration

Detection for a .ovpn file used in a malicious VPN client on victim machines by CharmingCypress.

APT / threat actorVolexity threat-intelBSD 2-Clause LicenseCompiles with YARA-X

Author: threatintel@volexity.com
Date: 2023-10-17
Modified: 2023-10-27
Score / Quality: 75 / 80

What this rule detects

Detection for a .ovpn file used in a malicious VPN client on victim machines by CharmingCypress.

It defines 3 patterns (3 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-malware-charmingcypress-openvpn-configuration.yarBSD 2-Clause License

rule VOLEXITY_Apt_Malware_Charmingcypress_Openvpn_Configuration : CHARMINGCYPRESS FILE
{
	meta:
		description = "Detection for a .ovpn file used in a malicious VPN client on victim machines by CharmingCypress."
		author = "threatintel@volexity.com"
		id = "f39b2d7c-f0c5-5623-a114-02ba32469e59"
		date = "2023-10-17"
		modified = "2023-10-27"
		reference = "TIB-20231027"
		source_url = "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/2024/2024-02-13 CharmingCypress/rules.yar#L273-L298"
		license_url = "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
		hash = "d6d043973d8843a82033368c785c362f51395b1a1d475fa4705aff3526e15268"
		hash = "31ca565dcbf77fec474b6dea07101f4dd6e70c1f58398eff65e2decab53a6f33"
		logic_hash = "f4c5f13ac75504b14def9c37d3a41c6eea4c45845d4b54c50030b1f00691e4bf"
		score = 75
		quality = 80
		tags = "CHARMINGCYPRESS, FILE"
		os = "all"
		os_arch = "all"
		scan_context = "file"
		severity = "high"
		license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
		rule_id = 9769
		version = 3

	strings:
		$remote = "remote-cert-tls server" ascii
		$ip = "Ip: "
		$tls = "<tls_auth>"

	condition:
		all of them
}

Strings (3 patterns)

Identifier	Type	Value	Modifiers
$remote	text	"remote-cert-tls server"	ascii
$ip	text	"Ip: "
$tls	text	"<tls_auth>"

Condition

all of them

In plain words (Heuristic)

All patterns in the rule must match.

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Sample hashes

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

d6d043973d8843a82033368c785c362f51395b1a1d475fa4705aff3526e15268
31ca565dcbf77fec474b6dea07101f4dd6e70c1f58398eff65e2decab53a6f33

Licence & attribution

Author: threatintel@volexity.com

Source repository: Volexity threat-intel @ 3a9d0b5245

Licence: BSD 2-Clause License (stated in the rule's own meta)

“See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt”

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: f39b2d7c-f0c5-5623-a114-02ba32469e59

Metadata

os	all
os_arch	all
scan_context	file
severity	high
rule_id	9769
version	3

Tags:CHARMINGCYPRESS FILE

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