YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_FE_APT_Webshell_PL_STEADYPULSE_1

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 / 85

What this rule detects

Detects samples mentioned in PulseSecure report

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

fe-apt-webshell-pl-steadypulse-1.yarDetection Rule License 1.1

rule SIGNATURE_BASE_FE_APT_Webshell_PL_STEADYPULSE_1
{
	meta:
		description = "Detects samples mentioned in PulseSecure report"
		author = "Mandiant"
		id = "49457fbb-9288-565f-909d-e8228c21c1e4"
		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#L265-L284"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "168976797d5af7071df257e91fcc31ce1d6e59c72ca9e2f50c8b5b3177ad83cc"
		logic_hash = "a0e3ebdd02ccf5cc8fc0a83c1d0224aed45dc5094eb85bd855e5b74b34e3aaaf"
		score = 75
		quality = 85
		tags = ""

	strings:
		$s1 = "parse_parameters"
		$s2 = "s/\\+/ /g"
		$s3 = "s/%(..)/pack("
		$s4 = "MIME::Base64::encode($"
		$s5 = "$|=1;"
		$s6 = "RC4("
		$s7 = "$FORM{'cmd'}"

	condition:
		all of them
}

Strings (7 patterns)

Identifier	Type	Value
$s1	text	"parse_parameters"
$s2	text	"s/\\+/ /g"
$s3	text	"s/%(..)/pack("
$s4	text	"MIME::Base64::encode($"
$s5	text	"$\|=1;"
$s6	text	"RC4("
$s7	text	"$FORM{'cmd'}"

Condition

all of them

In plain words (Heuristic)

All patterns in the rule must match.

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

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).

168976797d5af7071df257e91fcc31ce1d6e59c72ca9e2f50c8b5b3177ad83cc

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: 49457fbb-9288-565f-909d-e8228c21c1e4

SIGNATURE_BASE_M_APT_Downloader_BEATDROP
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2022-04-28
SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_1
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_2
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_3
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_4
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_5
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
SIGNATURE_BASE_APT_NK_MAL_M_Hunting_VEILEDSIGNAL_6
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-04-20
SIGNATURE_BASE_APT_UNC4736_NK_MAL_TAXHAUL_3CX_Apr23_1
APT / threat actorSignature Base (Florian Roth / Nextron)· Mandiant· 2023-03-04