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SEKOIA_Implant_Win_Havoc_Default_Strings

Finds Havoc implants based on the embedded default strings

MalwareHavocSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2022-10-07
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Finds Havoc implants based on the embedded default strings

Associated malware family: Havoc.

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

implant-win-havoc-default-strings.yarDetection Rule License 1.1
rule SEKOIA_Implant_Win_Havoc_Default_Strings : FILE
{
	meta:
		description = "Finds Havoc implants based on the embedded default strings"
		author = "Sekoia.io"
		id = "955c2211-4502-4258-ba4c-0d96a5624283"
		date = "2022-10-07"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/implant_win_havoc_default_strings.yar#L1-L23"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "dbf17e579071f265961657d73c6a2e51630b23e80376491df2e631cee5ffb1b4"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$str01 = "C:\\Windows\\System32\\notepad.exe" ascii
		$str02 = "C:\\Windows\\SysWOW64\\notepad.exe" ascii
		$str03 = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36" ascii
		$str04 = "POST" wide
		$str05 = "\\??\\C:\\Windows\\System32\\ntdll.dll" wide
		$str06 = "X-Havoc: true" ascii
		$str07 = "X-Havoc-Agent: Demon" ascii
		$str08 = "/text.gif" ascii
		$str09 = "SeImpersonatePrivilege" ascii

	condition:
		uint16( 0 ) == 0x5A4D and 6 of them
}

Strings (9 patterns)

IdentifierTypeValueModifiers
$str01text"C:\\Windows\\System32\\notepad.exe"ascii
$str02text"C:\\Windows\\SysWOW64\\notepad.exe"ascii
$str03text"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36"ascii
$str04text"POST"wide
$str05text"\\??\\C:\\Windows\\System32\\ntdll.dll"wide
$str06text"X-Havoc: true"ascii
$str07text"X-Havoc-Agent: Demon"ascii
$str08text"/text.gif"ascii
$str09text"SeImpersonatePrivilege"ascii

Condition

uint16( 0 ) == 0x5A4D and 6 of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least 6 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: 955c2211-4502-4258-ba4c-0d96a5624283

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE

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