Skip to content
yararules.org
Menu

YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_SUSP_Jdniexploit_Indicators_Dec21

Detects indicators of JDNI usage in log files and other payloads

Suspicious / huntingSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth (Nextron Systems)
Date
2021-12-10
Modified
2021-12-12
Score / Quality
70 / 85

What this rule detects

Detects indicators of JDNI usage in log files and other payloads

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
susp-jdniexploit-indicators-dec21.yarDetection Rule License 1.1
rule SIGNATURE_BASE_SUSP_Jdniexploit_Indicators_Dec21 : FILE
{
	meta:
		description = "Detects indicators of JDNI usage in log files and other payloads"
		author = "Florian Roth (Nextron Systems)"
		id = "2df8b8f3-8d8d-5982-8c85-692b7d91ebb2"
		date = "2021-12-10"
		modified = "2021-12-12"
		reference = "https://github.com/flypig5211/JNDIExploit"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_log4j_cve_2021_44228.yar#L167-L180"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "7886a67672001f0db72575d96d3a12341bfcdc49a9951e3d5e2a88ab46bf5a5d"
		score = 70
		quality = 85
		tags = "FILE"

	strings:
		$xr1 = /(ldap|ldaps|rmi|dns|iiop|http|nis|nds|corba):\/\/[a-zA-Z0-9\.]{7,80}:[0-9]{2,5}\/(Basic\/Command\/Base64|Basic\/ReverseShell|Basic\/TomcatMemshell|Basic\/JBossMemshell|Basic\/WebsphereMemshell|Basic\/SpringMemshell|Basic\/Command|Deserialization\/CommonsCollectionsK|Deserialization\/CommonsBeanutils|Deserialization\/Jre8u20\/TomcatMemshell|Deserialization\/CVE_2020_2555\/WeblogicMemshell|TomcatBypass|GroovyBypass|WebsphereBypass)\//

	condition:
		filesize < 100MB and $xr1
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$xr1regex/(ldap|ldaps|rmi|dns|iiop|http|nis|nds|corba):\/\/[a-zA-Z0-9\.]{7,80}:[0-9]{2,5}\/(Basic\/Command\/Base64|Basic\/ReverseShell|Basic\/TomcatMemshell|Basic\/JBoss …

Condition

filesize < 100MB and $xr1

In plain words (Heuristic)

  • The file must be smaller than 100MB (a cheap guard that skips large files).
  • Pattern $xr1 must be present.

Test this rule in your browser

Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.

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

Open in editor

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: 2df8b8f3-8d8d-5982-8c85-692b7d91ebb2

Tags:FILE

Related rules