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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_MAL_CN_Wocao_Webshell_Webinfo

Generic strings from webinfo.war webshells

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Fox-IT SRT
Date
2019-12-20
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Generic strings from webinfo.war webshells

It defines 8 patterns (8 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

apt-mal-cn-wocao-webshell-webinfo.yarDetection Rule License 1.1
rule SIGNATURE_BASE_APT_MAL_CN_Wocao_Webshell_Webinfo
{
	meta:
		description = "Generic strings from webinfo.war webshells"
		author = "Fox-IT SRT"
		id = "b8477f62-f3f6-5526-b0e3-9b794fefaa1f"
		date = "2019-12-20"
		modified = "2023-12-05"
		reference = "https://www.fox-it.com/en/news/whitepapers/operation-wocao-shining-a-light-on-one-of-chinas-hidden-hacking-groups/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_op_wocao.yar#L374-L394"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "711737a56067f24f422cc7d5aeba4389741fe18a0e66f2715fce626c3b6aef19"
		score = 75
		quality = 85
		tags = ""

	strings:
		$var1 = "String strLogo = request.getParameter"
		$var2 = "String content = request.getParameter(\"content\");"
		$var3 = "String basePath=request.getScheme()"
		$var4 = "!strLogo.equals("
		$var5 = "if(path!=null && !path.equals(\"\") && content!=null"
		$var6 = "File newfile=new File(path);"
		$str1 = "Save Success!"
		$str2 = "Save Failed!"

	condition:
		2 of ( $var* ) or ( all of ( $str* ) and 1 of ( $var* ) )
}

Strings (8 patterns)

IdentifierTypeValueModifiers
$var1text"String strLogo = request.getParameter"
$var2text"String content = request.getParameter(\"content\");"
$var3text"String basePath=request.getScheme()"
$var4text"!strLogo.equals("
$var5text"if(path!=null && !path.equals(\"\") && content!=null"
$var6text"File newfile=new File(path);"
$str1text"Save Success!"
$str2text"Save Failed!"

Condition

2 of ( $var* ) or ( all of ( $str* ) and 1 of ( $var* ) )

In plain words (Heuristic)

  • All patterns in ( $str* ) must match.
  • At least 2 patterns in ( $var* ) must match.
  • At least 1 patterns in ( $var* ) must match.

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References

Licence & attribution

Author: Fox-IT SRT

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: b8477f62-f3f6-5526-b0e3-9b794fefaa1f