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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_LOG_APT_WEBSHELL_Solarwinds_SUNBURST_Report_Webshell_Dec20_2

Detects webshell access mentioned in FireEye's SUNBURST report

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth (Nextron Systems)
Date
2020-12-21
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Detects webshell access mentioned in FireEye's SUNBURST report

It defines 1 patterns (0 text, 0 hex, 1 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
log-apt-webshell-solarwinds-sunburst-report-webshell-dec20-2.yarDetection Rule License 1.1
rule SIGNATURE_BASE_LOG_APT_WEBSHELL_Solarwinds_SUNBURST_Report_Webshell_Dec20_2
{
	meta:
		description = "Detects webshell access mentioned in FireEye's SUNBURST report"
		author = "Florian Roth (Nextron Systems)"
		id = "fb86164d-13de-5357-8f52-c597b51127ff"
		date = "2020-12-21"
		modified = "2023-12-05"
		reference = "https://www.guidepointsecurity.com/supernova-solarwinds-net-webshell-analysis/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_solarwinds_susp_sunburst.yar#L21-L32"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "ec52e244a483ace0f6932b553b159b23b767c00d1f64a4711e5f359832e846f5"
		score = 75
		quality = 85
		tags = ""

	strings:
		$xr1 = /logoimagehandler.ashx[^\n\s]{1,400}clazz=/ ascii wide

	condition:
		$xr1
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$xr1regex/logoimagehandler.ashx[^\n\s]{1,400}clazz=/ascii wide

Condition

$xr1

In plain words (Heuristic)

  • Pattern $xr1 must be present.

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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: fb86164d-13de-5357-8f52-c597b51127ff

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