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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_SUSP_Base64_Encoded_Hacktool_Dev

Detects a suspicious base64 encoded keyword

Suspicious / huntingSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth (Nextron Systems)
Date
2020-06-10
Modified
2026-05-15
Score / Quality
65 / 85

What this rule detects

Detects a suspicious base64 encoded keyword

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
susp-base64-encoded-hacktool-dev.yarDetection Rule License 1.1
rule SIGNATURE_BASE_SUSP_Base64_Encoded_Hacktool_Dev : FILE
{
	meta:
		description = "Detects a suspicious base64 encoded keyword"
		author = "Florian Roth (Nextron Systems)"
		id = "6dc7db4b-a614-51e4-a9a5-f869154dbbb1"
		date = "2020-06-10"
		modified = "2026-05-15"
		reference = "https://twitter.com/cyb3rops/status/1270626274826911744"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/gen_susp_obfuscation.yar#L117-L137"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "7345a528a12f87e5cbcabccf649566a038dd2115e8aec4f39599e357c8c6d57f"
		score = 65
		quality = 85
		tags = "FILE"

	strings:
		$ = "QGdlbnRpbGtpd2" ascii wide
		$ = "BnZW50aWxraXdp" ascii wide
		$ = "AZ2VudGlsa2l3a" ascii wide
		$ = "QGhhcm1qMH" ascii wide
		$ = "BoYXJtajB5" ascii wide
		$ = "AaGFybWowe" ascii wide
		$ = "IEBzdWJ0ZW" ascii wide
		$ = "BAc3VidGVl" ascii wide
		$ = "gQHN1YnRlZ" ascii wide

	condition:
		filesize < 6000KB and 1 of them
}

Strings (9 patterns)

IdentifierTypeValueModifiers
$text"QGdlbnRpbGtpd2"ascii wide
$text"BnZW50aWxraXdp"ascii wide
$text"AZ2VudGlsa2l3a"ascii wide
$text"QGhhcm1qMH"ascii wide
$text"BoYXJtajB5"ascii wide
$text"AaGFybWowe"ascii wide
$text"IEBzdWJ0ZW"ascii wide
$text"BAc3VidGVl"ascii wide
$text"gQHN1YnRlZ"ascii wide

Condition

filesize < 6000KB and 1 of them

In plain words (Heuristic)

  • The file must be smaller than 6000KB (a cheap guard that skips large files).
  • At least 1 patterns in the rule must match.

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References

Licence & attribution

Author: Florian Roth (Nextron Systems)

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

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: 6dc7db4b-a614-51e4-a9a5-f869154dbbb1

Tags:FILE

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