YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_FE_APT_Webshell_PL_HARDPULSE

Detects samples mentioned in PulseSecure report

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X

Author: Mandiant
Date: 2021-04-16
Modified: 2023-12-05
Score / Quality: 75 / 83

What this rule detects

Detects samples mentioned in PulseSecure report

It defines 7 patterns (4 text, 0 hex, 3 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

fe-apt-webshell-pl-hardpulse.yarDetection Rule License 1.1

rule SIGNATURE_BASE_FE_APT_Webshell_PL_HARDPULSE
{
	meta:
		description = "Detects samples mentioned in PulseSecure report"
		author = "Mandiant"
		id = "f9a2922e-6b8e-5f92-a947-3215ee8883ac"
		date = "2021-04-16"
		modified = "2023-12-05"
		reference = "https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_pulsesecure.yar#L46-L65"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "980cba9e82faf194edb6f3cc20dc73ff"
		logic_hash = "37fc40fd998d3294edb05707170bc2deec524fc6451bff212901f9ac3e34bb35"
		score = 75
		quality = 83
		tags = ""

	strings:
		$r1 = /if[\x09\x20]{0,32}\(\$\w{1,64}[\x09\x20]{1,32}eq[\x09\x20]{1,32}[\x22\x27]\w{1,64}[\x22\x27]\)\s{0,128}\{\s{1,128}my[\x09\x20]{1,32}\$\w{1,64}[\x09\x20]{0,32}\x3b\s{1,128}unless[\x09\x20]{0,32}\(open\(\$\w{1,64},[\x09\x20]{0,32}\$\w{1,64}\)\)\s{0,128}\{\s{1,128}goto[\x09\x20]{1,32}\w{1,64}[\x09\x20]{0,32}\x3b\s{1,128}return[\x09\x20]{1,32}0[\x09\x20]{0,32}\x3b\s{0,128}\}/
		$r2 = /open[\x09\x20]{0,32}\(\*\w{1,64}[\x09\x20]{0,32},[\x09\x20]{0,32}[\x22\x27]>/
		$r3 = /if[\x09\x20]{0,32}\(\$\w{1,64}[\x09\x20]{1,32}eq[\x09\x20]{1,32}[\x22\x27]\w{1,64}[\x22\x27]\)\s{0,128}\{\s{1,128}print[\x09\x20]{0,32}[\x22\x27]Content-type/
		$s1 = "CGI::request_method()"
		$s2 = "CGI::param("
		$s3 = "syswrite("
		$s4 = "print $_"

	condition:
		all of them
}

Strings (7 patterns)

Identifier	Type	Value
$r1	regex	/if[\x09\x20]{0,32}$\$\w{1,64}[\x09\x20]{1,32}eq[\x09\x20]{1,32}[\x22\x27]\w{1,64}[\x22\x27]$\s{0,128}\{\s{1,128}my[\x09\x20]{1,32}\$\w{1,64}[\x09\x20]{0,32}\ …
$r2	regex	/open[\x09\x20]{0,32}\(\*\w{1,64}[\x09\x20]{0,32},[\x09\x20]{0,32}[\x22\x27]>/
$r3	regex	/if[\x09\x20]{0,32}$\$\w{1,64}[\x09\x20]{1,32}eq[\x09\x20]{1,32}[\x22\x27]\w{1,64}[\x22\x27]$\s{0,128}\{\s{1,128}print[\x09\x20]{0,32}[\x22\x27]Content-type/
$s1	text	"CGI::request_method()"
$s2	text	"CGI::param("
$s3	text	"syswrite("
$s4	text	"print $_"

Condition

all of them

In plain words (Heuristic)

All patterns in the rule must match.

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References

https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

980cba9e82faf194edb6f3cc20dc73ff

Licence & attribution

Author: Mandiant

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: f9a2922e-6b8e-5f92-a947-3215ee8883ac

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APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
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Identifier	Type	Value
$r1	regex	/if[\x09\x20]{0,32}\(\$\w{1,64}[\x09\x20]{1,32}eq[\x09\x20]{1,32}[\x22\x27]\w{1,64}[\x22\x27]\)\s{0,128}\{\s{1,128}my[\x09\x20]{1,32}\$\w{1,64}[\x09\x20]{0,32}\ …
$r2	regex	/open[\x09\x20]{0,32}\(\*\w{1,64}[\x09\x20]{0,32},[\x09\x20]{0,32}[\x22\x27]>/
$r3	regex	/if[\x09\x20]{0,32}\(\$\w{1,64}[\x09\x20]{1,32}eq[\x09\x20]{1,32}[\x22\x27]\w{1,64}[\x22\x27]\)\s{0,128}\{\s{1,128}print[\x09\x20]{0,32}[\x22\x27]Content-type/
$s1	text	"CGI::request_method()"
$s2	text	"CGI::param("
$s3	text	"syswrite("
$s4	text	"print $_"